Wrist Straps – Ground Zero Electrostatics Blog

04 Aug

Managing Static and ESD in Call Centers

Thanks to movies and TV, no matter how old you are, you’ve probably seen the old switchboards – whether it’s on Agent Carter or reruns of the Andy Griffith Show – and computers that barely fit inside a room – like in The Imitation Game or the TV show Manhattan.

Nowadays, of course, we carry the switchboard and the computer in a handy-dandy pocket device.

Likewise with emergency services. When we call 9-11, we expect a prompt response, and the person on the other end of the line assures us that police, fire, or ambulance are already in route as they continue to gather our information.

Computers help planes land, monitor traffic on the freeways, and even park your car for you.

But for all the advances in technology, there have been setbacks as well.

In the old days, phone and computer systems were built “solid-state.” Everything was confined within one unit and was protected from outside forces. Internally, they were defended from ElectroStatic Discharge (ESD) by microcircuit gate protectors.

Unfortunately, these gate protectors, while highly effective, tended to slow down the machines they were protecting – kind of like how some companies’ virus protection forces their machines to crawl.

As technology progressed, emergency services, military bases, and flight control centers started abandoning these more stringent preventative measures, in favor of speed.

The end result being, while these computers and call centers are protected in buildings made to withstand hurricanes, earthquakes and power outages, they can be disabled or even rendered completely useless by the tiniest static shock.

Which is why the proper ESD protection and protocols are so important in these mission critical locations.

Another factor to consider is that these facilities are typically open 24-hours a day and have hundreds of people pass through them on a regular basis. Some of them are trained and properly equipped with ESD shoes, heel grounders and even personal wrist straps, but certainly not all of them.

And when there’s a crisis and everyone needs to scramble to get the problem solved, the first thing to go is proper ESD procedures.

The answer is to make these facilities as static proof (or charge proof) as possible.

Like your skin (the largest organ in the human body), flooring is the largest and most vulnerable area for ESD buildup and discharge, if it’s not handled properly.

There are many options for ESD flooring, as we’ve discussed in prior posts, but in this instance, there are really only one option: carbon-fiber laced carpet.

The first thing you should know is that not all ESD carpet is created equal. Some companies promote and sell an ESD carpeting that is treated with a chemical to reduce static that disintegrates over time and must be reapplied.

Avoid these – you don’t want your static protection to be subject to a random timetable. Again, these facilities are always open. You’ll want to invest in a carpet whose static-prevention comes from the permanent physical composition of the materials.

For the same reason, you’ll want to invest in an ESD carpeting that is certified by ANSI/ESDA standards and reduces static regardless of the humidity levels or footwear worn by the personnel.

As an added bonus look for ESD carpet that is low maintenance, crush resistant, able to handle heavy foot traffic and comes with a lifetime warranty.

Contact us today for more information or to talk about your ESD flooring options. We would love to be your full service, seamless ESD solution provider.

25 May

What Are the Standards for Electrostatic Protection?

So, you’ve just been tasked with building or designing your first Electrostatic Protection Area (EPA). You’ve started doing your research, but there are so many choices, from so many different companies. Suppliers, manufacturers, third party providers… If only there was some established standard for judging the efficacy and reliability of all those pieces and parts.

Well, you’re in luck! In 2007, the American National Standards Institute (ANSI) in cooperation with ElectroStatic Discharge Association (ESDA) released a unified set of standards for the design, implementation and maintenance of ElectroStatic Discharge control programs.

In the midst of World War I, five engineering organizations recognized the need to develop standards that could eliminate confusion and could be adhered to across all disciplines, without regard to politics, profits or personal preferences. These groups reached out to the U.S. Departments of War, Navy, and Commerce to form an impartial third party non-profit organization, then known as the American Engineering Standards Committee.

Following the war, the organization spent the next 20 years establishing several safety protocols still observed today, like eye protection, hard hat standards and in-house electrical safety while at the same time reaching out to other similarly tasked international organizations.

When the United States entered World War II, the organization, which would eventually come to be known as ANSI, helped to accelerate the war effort and productivity, created more effective quality control measures, as well as helping to advance photography, radio, and even the development of Velcro.

In 1970’s, ANSI established a public review process and began the herculean effort of moving the United States to the metric system. While the general public never really connected with the metric system, the effort did bring ANSI to the forefront of private sector companies who discovered standardization was a way to stay more competitive in an increasingly global economy.

With the advancement of personal computers in the late 70’s and early 80’s, engineers at several companies recognized a need for more understanding of electrostatic discharge and its prevention. They formed the ESD Association, a non-profit, voluntary professional organization that for almost 35 years has sponsored educational programs and developed standards to help eliminate losses due to electrostatic discharges.

Together, leaning on the historical experience of both military and several commercial organizations, ANSI and ESDA developed the definitive standard for ESD protection, the very cleverly named ANSI/ESD S20.20-2007.

Covering about every conceivable area of ElectroStatic Discharge, the ANSI/ESD S20.20-2007 utilizes both the human body model and the machine model to provide a broad set of guidelines for ESD protection.

The Human Body Model is the military standard that defines and rates the vulnerability of an electronic device to the ESD generated by a human being touching it. The Machine Model works similarly, except it rates the vulnerability of a device receiving a machine discharge into ground. It was originally developed by car manufacturers as their plants moved to more mechanized production technology. The Human Body Model is about 10 times more sensitive than the Machine Model.

There is a lot to explore in the ANSI/ESD S20.20-2007 guidelines, but for the purpose of this primer, the document highlights 3 fundamental ESD control principles:

All conductors should be grounded. This includes the personnel and the surfaces they are working on. We recommend, at a minimum, personal grounding wrist straps, ESD table or bench mats, and a common ground cord.
Necessary non-conductors – certain circuit board materials, device packaging, etc. – cannot lose their electrostatic charge by being grounded and appropriate precautions must be implemented.
Static protective materials, such as ESD shielding bags or ESD totes and boxes must be utilized when transporting sensitive electronics outside a properly prepared EPA.

There are slightly less stringent standards that apply to floors and bench mats, but ANSI/ESD S20.20-2007 is the highest and most comprehensive guideline so far. So when you’re shopping for the parts needed to establish your EPA area, always look for companies that maintain that standard in their products and services.

We would love to be your full service, seamless ESD solution provider; contact us today for more information.

04 May

Finding ESD Storage Solutions

There’s a classic scene that appears, with some variation, in every James Bond film. Bond gets assigned a new mission and he goes to see MI-6’s Quartermaster, or “Q.” Q gives Bond everything he needs to complete the mission, including a few items that seem unusual or out of place.

Of course, as Bond fans know, these elements will at some point be combined to facilitate a distraction so Bond can escape. And usually that distraction is a rather large explosion.

One wonders how he was transporting the items before so that they didn’t explode in his Armani suit.

Of course, in real life, when items combine, the result isn’t usually an explosion. Or is it?

As we’ve mentioned before, the amount of Electrostatic Discharge (ESD) required to cause significant damage to sensitive electronics is far below the threshold where a human being can feel it.

By the time our bodies create a static charge that we can feel, it’s somewhere between 3 & 17 times stronger than what most electronics can handle without suffering damage.

Even just the controlled blowing of air, like the old canned air computer dust removal techniques can cause static ESD build-up that can be transferred to your sensitive electronics. And that tiny electrostatic discharge can cause latent or catastrophic failure, costing you time and money.

We’ve discussed selecting the proper shielding bags in a previous post. Another important weapon in your Electrostatic Discharge defense arsenal is anti-static ESD storage containers.

ESD Storage Containers

ESD storage containers are typically made of a conductive material, such as polypropylene or high density polyethylene and provide an added layer of protection, shielding your work areas and personnel from the harmful effects of ESD.

The conductive material provides a barrier which these fields cannot penetrate and prevents the build-up of electrostatic charge. The bins, totes and miscellaneous storage containers come in both static dissipative and conductive. Both control a potential electrostatic discharge, one by resisting it, the other by neutralizing it.

Additionally, be on the lookout for non-ESD protected items that may stray into the Electrostatic Protected Area – transparent tape, plastic sandwich bags, water bottles, Styrofoam coffee cups, even just pieces of paper – can be the source of an uncontrolled electrostatic discharge.

Of course, all of these storage solutions should be used within the minimum guidelines of an Electrostatic Protection Area, that is, wrist straps, ESD mats and a common ground.

We would love to be your full service, seamless ESD solution provider; contact us today for more information.

05 Apr

The Truth About 11 Myths of Electrostatic Discharge: Part 2

Last week we shared with you Part 1 of The Truth About 11 Myths of Electrostatic Discharge; here’s Part 2…

Myth #6 – An ESD bag is all the protection I need.

There is a somewhat popular belief that you can use the ESD shielding bag that your circuit board or sensitive electronics was shipped in as adequate “matting” when you are working. This could not be more false.

Regardless of which ESD shielding bag you receive or purchase, it ONLY provides ESD protection while the item in entirely enclosed inside a sealed bag. Outside of the bag, it can actually increase the chances that you will generate an ESD event, because the bag is designed to “push” a charge away from the contents of the bag – right into your electronics.

Myth #7 – Grounded metal offers a safe haven from ESD.

In fact, conductive materials – like metals – are not safe surfaces for sensitive electronic components that could be subject to an electrostatic charge, even if they are grounded. In fact, the charge dissipation is so fast, the resistance to ground has almost zero impact.

The point of grounding is to get everything at the same potential energy level so that current from an ESD can’t flow where it shouldn’t. Using metal, even grounded metal, voids this effort.

The next three myths are similar in nature…

Myth #8 – Circuit boards without complementary metal oxide semi-conductor (CMOS) are safe.

On its face, this seems obvious, as it is hard to find a circuit board without some CMOS components. However, ALL circuit boards are susceptible to electrostatic discharges and the damage they can cause.

Myth #9 – A printed wiring board (PWB) permanently protects a circuit board.

Just because a component is inserted into a PWB, that does not protect it from potential ESD damage. It does decrease the likelihood that fatal loss will occur, as the voltage the entire board can sustain is increased.

But this is by no means a guarantee of safety. All proper precautions must be taken when handling sensitive electronics.

Myth #10 – Once products are mounted on circuit boards, ESD mishaps cannot occur.

This is similar to the above myth. But unlike PWB boards, unprinted boards can actually leave sensitive components even more vulnerable because there is less resistance to slow the electrostatic discharge down.

Myth #11 – Small companies cannot afford proper ESD protection.

On the contrary, small companies cannot afford not to have suitable ESD protocols and tools. The risk of damage and the costs associated with it are just too excessive not to invest in the proper implementation of an ESD protected workstation – even a portable one, if need be.

We recommend at a minimum, personal grounding wrist straps, dissipative ESD matting and grounding cables.

We would love to be your full service, seamless ESD solution provider, no matter what your size or budget. Contact us today for more information.

25 Feb

Building an Electrostatic Protected Area (EPA)

Almost everyone’s familiar with the image of a white “cleanroom” or “bunny suit.” They show up in just about every depiction of people working in computer facilities in popular entertainment, and it’s a highly sought after specialty ‘armor’ in the video game Fallout 4.

What most people may not know is that the suits are designed not to protect the person inside, but the delicate circuitry they’re working on. But not everyone who works with small, sensitive electronics needs to spend money for a full-on, disposable suit.

If you work with a lot of small electronics, a more affordable solution is to put together an electrostatic protected area (or EPA). This doesn’t have to take up a lot of space and can actually be quite portable. It just needs to be done properly.

Let’s start with the basics and work our way up to the safest and most expensive options.

Simple EPA

At a bare minimum, all personnel working within an EPA should have a personal grounding wrist strap. These make sure any excess energy is grounded – forced away – from the electronic devices and circuit boards being handled.

Connected to that grounding strap is a dissipative mat. Dissipative means quite simply to disperse or disappear. A properly designed and implemented dissipative mat does for the surface what the grounding wrist strap does for the person – protects sensitive electronics from electrical discharges.

Mats can be purchased pre-cut or in rolls, depending on what your needs are.

Attached to both of these is a common point cord, also referred to as a grounding cord. These cords are fully insulated and take any electrostatic charges away from the person and the ESD mat to be grounded safely.

Often these simple options are packaged together as a field service or workstation kit that can be purchased as one unit to avoid forgetting any key elements.

Now that we’ve established the minimum requirements for an EPA, let’s look at additional options that can be easily implemented within your system to further insure the safety of the components and reduce the risk and excess cost of replacement.

From the Ground Up

For more permanent EPA installations, there are a variety of flooring options that can be integrated. Everything from conductive and dissipative vinyl tiles to anti-static carpeting that can be utilized in the work area or just in the area surrounding your EPA system. You can even add flooring with a high-end moisture barrier as well as anti-static protection.

Sole Protection

One of the most obvious ways we build up a potentially dangerous electrostatic discharge is just by walking. Static charges build up naturally. While a personal grounding wrist strap will help dissipate the charge, there are additional options for your feet.

Shoe covers with conductive strips are a quick, low cost addition to an existing EPA system and great for alleviating the risk of allowing visitors into the EPA area.

For employees whose duties mean they spend substantial time in the EPA area, you can add foot and heel grounders, toe grounders and sole grounders.

For even more protection, grounders can be upgraded to ESD shoes. These come in a variety of styles for your business setting – even weatherproof boots and hiking models.

Additional Considerations

Adding isolation protocols and ESD protective containers can also complement your EPA system and reduce the chance of any accidental charges building up or discharging into your electronic components.

Of course grounding should be a consideration with any additions to your EPA system. Whether it’s flooring or matting, grounding cords with a built in resistor add that much more protection to your area. And the more working parts you have, the more grounding capability you require.

There are simple options to increase the grounding ability of any size EPA system, as well as monitors that can be added to the system – at the personal or system-wide level.

And if you really feel the need to cover yourself top to bottom, there are more workable clothing options as well.

Contact us today for more information; we would love to be your full service, seamless ESD solution provider.

12 Feb

ESD: Grounding, Isolation & Prevention

The Pilllars of ESD Protection

We’ve all had it happen. We’re opening our car door on a cold day, or we’ve just shuffled in our socks to the door and the moment we reach out, pop! A small snap of static electricity reminds us that we’re alive.

Think back to when you were a kid – your dad or uncle perhaps, showed you the power of static electricity by rubbing a balloon on your head and sticking it to the wall or causing your hair to rise up of its own accord. These tricks with static electricity are great for a chuckle or two. When you’re rubbing the balloon or your socks on the floor, it creates an imbalance of electrons, and that potential energy rests on your body or the surface of the balloon, waiting to discharge. Eventually it does and this sudden restoring of the electrons to their neutral state is called an electrostatic discharge or ESD.

That little tiny jolt of static electricity seems small but is really 3,000 volts – for humans, it’s the amperage that gets you. Unfortunately, for small electronics: circuit boards, semiconductors or even simple devices around the home, much smaller static discharges – ones too light to ever be sensed by our skin – can cause minor errors, or even completely destroy a device’s usefulness. In this situation, ESD is no laughing matter.

In a business—especially one that manufactures or handles a lot of electronics, but even in a typical office environment—this kind of damage can get expensive quickly.

So today, we’re going to talk about the three pillars of controlling ESD: Grounding, Isolation and Prevention.

Grounding

If you’ve worked with small electronics much at all, you’re probably aware that there are certain things you should do to prevent damage to that circuitry. You’re probably familiar with the third prong on many electrical cords. Just like the grounding plug diminishes the risk of you being electrocuted, grounding yourself and your work area keeps your circuit boards and electrical components safe by discharging any built up static electricity.

At a bare minimum, utilizing a grounding wrist band is extremely helpful. Many sellers include disposable bands when they ship electronic components, but we highly recommend owning and utilizing your own personal metal ground wrist strap that connects directly to your work surface with a personal ground cord. Always make sure the wrist strap is snug and is touching the skin to allow the charge to dissipate.

Isolation

Static charges cannot penetrate containers that are made of conductive materials or have a conductive layer. That’s why electronic components usually arrive in metallized shielding bags or a conductive tote box. Don’t forget you must ground them before opening. And don’t set these components just anywhere. What many people fail to realize is that simple items that can be found on any normal work surface – even an ESD mat – can also cause unnecessary static buildup that could lead to a fatal discharge.

Transparent tape, plastic sandwich bags, water bottles, Styrofoam coffee cups, even paperwork or blueprints can hold a static charge just waiting to wreak havoc on unsuspecting components. And even if you are properly grounded, holding the components too close to your clothing can also result in an ESD.

Prevention

Always take proper precautions when working on electronic components. Follow all of the tips above, and if you’re going to be working on several components or multiple projects, we recommend investing in some ESD bench and table matting for your work surface. It integrates well with a personal ground cord and wrist band and is the best solution for ESD prevention. A few dollars spent here as well as on ESD protective containers can mean plenty of money saved on ruined components as well as lost time while waiting for replacements.

Following these simple suggestions can mean a much safer environment for both you and your electronic components – and you can leave the static charge at home for parlor tricks.

Contact us today for more information; we would love to be your full service, seamless ESD solution provider.

18 Jun

We don't need no stinking wrist straps, do we?

Q: I have read the White Paper 1: A Case for Lowering Component Level HBM/MM ESD Specifications and Requirements and found the ESD Control Programs and Resulting Data (Chapter 1, Page 20-23) particularly interesting.

Assuming a production environment with ESD flooring, footwear (and clothing), by the time a person walks to a workstation and sits down, the voltage of this persons should not exceed 500V (or even 100V as seen in Figure 3). That would mean even a seated operator in this case would not need to wear wrist strap, that theory would be correct right? After sitting down and this person sits on a stool (feet off the floor) with resistance to floor < 1.0x10exp9ohms, any HBM risk would be further reduced wouldn’t it?

A: Hello ****. Nice try. Even if you have an ESD flooring system and even if you have ESD footwear and even if you have an ESD task chair with ESD casters or an ordinary task chair with an ESD chair cover (very effective as well), ESD smock on… you STILL have to wear the wrist strap when seated at an ESD workstation.

The only time, per ANSI/ESD S20.20-2007 page 4, 8.2 Personnel Grounding, that personnel in the EPA (ESD Protected Area) should be without a wrist strap is when doing standing or walking about operations, and then two conditions must be met;
· “When the total resistance of the system (from the person, through the footwear and flooring to the grounding / Equipotential bonding system) is less than 3.5E7 Ω…”
· “When the total resistance of the system (from the person, through the footwear and flooring to the grounding / Equipotential bonding system) is greater than 3.5E7 Ω and less than 1.0E9 Ω and the BVG is less than 100 v per 97.2…”

This is what is said about seated personnel:

“When personnel are seated at ESD protective workstations, they shall be connected to the grounding / Equipotential bonding system via a wrist strap system.”

Hope this helps. I guess you could say redundancy is good in the realm of ESD. It’s the weak link in the chain that will cause an ESD event. If someone lifts their ESD footwear from the ESD flooring system while seated, they can tribocharge to above 100 volts. It takes only 0.3 seconds of charge time to exceed 20.20 requirements. If personnel is seated and getting up to go to break, it seems best to stand up, remove the wrist strap from the wrist, carefully set it down and walk away from the ESD workstation. Worst case is to take the wrist strap off while still seated, set it down, put your hand on the ESD workstation and near ESDS devices, then stand up out of the task chair before leaving the work station. Under proper conditions and with good bench mats, clean ESD floors, ESD task chairs, etc. in place, no ESD event. The problem with ESD events is that we cannot see, hear, feel them.

The only alternative to not wearing a wrist strap while seated may be the used of a smock with a grounding coil cord attached to it. You can see the footnotes on the 20.20 document at the bottom of page 4 for further details.

We adhere to and meet or exceed requirements put forth in ANSI/ESD S20.20-2007 or IEC 61340-5-1, which assumes a target HBM of 100 volts and less.

05 Dec

Ground Rod-to-earth resistance

Q: What should be the required Ground Rod-to-earth resistance? is it less than 2ohms or less than 25ohms?

A: I am going to consult my document on Grounding-For the Protection of Electrostatics Discharge Susceptible Items (ANSI/ESD S6.1-2005), an ESD Association standard. I am assuming that your inquiry is to provide the bonding and grounding for the prevention of ESD in an EPA (ESD Protected Area).

From the Main(s) service equipment or AC Mains, you have the Hot or Black conductor (Let’s assume AC Single Phase 120v) from the Circuit breaker panel, then you have the Neutral or white conductor coming from the Neutral bus, then you have the Equipment grounding conductor or green conductor. The black or Hot conductor comes from a circuit breaker and goes to an AC outlet receptacle. The white or Neutral conductor comes from a neutral bus which is bonded to an earth grounding electrode and goes to an AC outlet receptacle. The green conductor or equipment grounding conductor comes from a ground bus and is bonded to the metal chassis or conduit. The ground bus is then bonded to the Neutral bus. The common point ground or bus bar is connected or bonded to this ground connection, as is various other ESD technical elements (the grounding conductors or wires from wrist straps, worksurfaces, flooring or floor mats, tools, fixtures, storage units, carts, chairs, garments, etc).

The impedance of the equipment grounding conductor or receptacle ground to the common point ground or ESD technical element shall not be greater than 1 ohm (Ω). I see no mention of 2 ohms (Ω) in this document, although it is noted that the ground resistance values objectives vary from industry to industry. The telecommunications industry has often used 5 ohms or less as their value for grounding and bonding. The goal in grounding resistance values is to achieve the lowest ground resistance value possible. The National Electrical Code defines a ground as: “a conductive connection, whether intentional or accidental between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth.” The purpose of a ground besides the protection of people and equipment is to provide a safe path for the dissipation of Fault Currents, Lightning Strikes, Static Discharges, EMI and RFI signals and Interference.

The reference to 25 ohms refers to facilities with AC Equipment Ground and Auxiliary Ground (A separate supplemental grounding conductor for use other than general equipment grounding) per ANSI/ESD S6.1-2005 6.3.2. The auxiliary ground shall be bonded to the AC equipment ground when possible. The AC equipment and the ESD technical elements might be at different potentials. The auxiliary ground needs to be bonded to the equipment ground to ensure that there is no difference in electrical potential between the two systems.

05 Dec

Wrist straps according to EOS/ESD standards.

Q: We have an ESD tile floor in our testing lab. During a recent AS9100 audit we were asked why we don’t use wrist straps. Since our ISO9100 & 2 certified calibration provider only uses them when they have to certify the repair of a system and we don’t do that do we need more than the flooring? (booties, straps, etc.)

A: The answer to your question is, YES. In accordance to EOS/ESD standards, an ESD floor in conjunction with Heel Grounders, ESD Booties, ESD Foot Wear does NOT take the place of using Personnel grounded Wrist Straps at the workstation. So the basic ESD program would include the technician wearing a Wrist Strap.

Protective personnel grounding products such as; heel straps, booties and shoes working in conjunction with an ESD floor are designed for processes within your ESD program where the technician has to be mobile within an ESDPA, (ESD Protected Area) where the electrostatic sensitive device is not protected in an ESD protective container or shielded in some manner, e.g. ESD Bag, Bin, Tote, Box, Tray, Container, etc.

If your process has technical personnel setting or standing at a workstation they DO require grounding via a Wrist Strap. So one doesn’t necessarily take the place of the other, and both may be required depending on your personnel and their mobility throughout the plant.

If your technical staff removes their wrist strap to transport an ESD sensitive device or component outside the ESD protected area, the device also needs to be shielded as well as the technician being properly outfitted with ESD shoes, booties or heel straps. Within the ESDPA, they do require the additional shielding protection of the device, but it is always a good idea when practical.

I hope this helps address your question, please let us know if we can be of further assistance with any ESD questions or ESD protective product requirements you and your team may be sourcing.