25 Feb

Building an Electrostatic Protected Area (EPA)

How to Build an Electrostatic Protected Area

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.

04 Feb

How to measure ohms of ESD Chair back rest

Q: Hi, I am a fresh ESD engineer. I need to perform a testing on ESD chair by using 5 pound Megohmmeter. I encountered a problem when I was trying to test on the backrest and rear of backrest. The backrest is a vertical plate, how to put a 5 pound electrode perpendicular to that surface? Even ANSI/ESD STM 12.1 2006 also not mentioned clearly about the testing on the backrest. Can I hold the 5 pound electrode by my hands so that it is contact with surface of the backrest? Or is there any other proper way?”

A: Hello,  I understand your frustration with some of these tests.

It sounds like you’ve got all the proper testing equipment and you’re following the best procedures for this.  The main concern is to see that the seat, seat back and arms are making good contact to the personnel, that personnel is wearing the proper clothing so as to enable the combination of personnel to chair to esd flooring system to electrical ground are enabling the tribocharge to recombine to earth.  If you have an ESD chair that includes a static conductive/dissipative seat, back, arms, casters, etc. we can make these resistance measurements to the chair’s groundable point, to a plate sitting underneath a caster, and ultimately, all the way across the floor to earth ground.
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05 Dec

Using an ESD Chair when already protected

Q: Is it necessary to use an ESD Chair when the humany body is already grounded through a Wrist Strap, Footwear or Heel Strap when working in an EPA?

A: I think it’s a great idea.  I can be sitting at a workstation with an ESD flooring system, have a wrist strap on and when I get out of my chair, not generate more than 50 volts.  I may not generate more than 5 volts.  But what if I take my wrist strap off and jump out of my chair?  I can easily generate 100’s of volts.  Oh, by the way, jumping should not be allowed in an EPA.  If you have great ESD shoes or sole grounders and you keep at least one foot firmly planted on the ground at all times, then maybe your ESD chair is redundant, but still an added piece to the chain in your EPA system.