In the electronics repair industry, ESD (Electrostatic Discharge) is our enemy. Some electronics require more care, as the sensitivity through different systems varies widely. IC chips and other component level electronics can be damaged by anything between 100 and 2,000 volts. (Many people find it surprising that the static they build up while walking over carpet ranges from 15,000 to 30,000 Volts!) With this post I hope to touch base on ESD misconceptions and tips, so that we can better understand what we are trying to prevent, and how to best go about said prevention with your work station(s).
What is ESD? Electrostatic Discharge is the equalization of electric potential between any two objects. When two objects are differently charged and come close to one another, the dielectric between them breaks down, allowing for the transfer of energy. Simply put, Electrostatic Discharge is when the static that builds up on our bodies transfers to an object around us. The ‘shock’ we feel when we walk across the carpet and touch a doorknob is a great example of ESD. The cost of these tiny little shocks to the electronics industry has surpassed one billion dollars per year!
Fun Fact: When you reach for a doorknob and see a spark; the air between your hand and the knob has grown extremely hot from the quick movement of electrons. This instantly turns it to plasma, a fourth state of matter that differs from the common solids, gases, and liquids.
How do we prevent this in our workspace? Grounding. Unfortunately the term “grounding” is misunderstood, and is thus used freely and improperly in many instances. Without an understanding of the principles of grounding, it is impossible to set up a true ESD Safe workstation.
At the very least, your workstation(s) should include two ESD mats; one being a floor mat for under your feet and the second being a tabletop mat. These are made with dissipative materials such as vinyl, rubber or elastomer. These mats then typically have a ground wire, which allows for the mat to whisk static away from anything that they touch, similar to a sponge soaking up a liquid spill. Without properly grounding that wire, these ESD mats are doing very little in ESD prevention!
Grounding these mats can be done in a variety of ways. Another misconception is to tie your systems to an “earth ground”. This involves connecting your station to something which will disperse voltage to the, well, earth. While this does work and is used to shield many buildings which are prone to lightening strikes, it is not safe for repair use. Remember, you are connecting your body to this circuit. If a problem exists and that earth ground has to move high levels of electricity, you may not get the chance to perform too many more repairs.
The best method is to make use of an “electrical ground”. This is by far the most reliable ground, and can be easily tested for functionality. The Electrostatic Discharge Association (ESDA) sets the standards for removal of static, and they list electrical grounds as the Gold Standard. (To learn more about ESDA and their mission, visit https://www.esda.org)
ESD Is very real. If we don’t ground ourselves, we risk irreversible damage to the devices. And remember, we may not be able to see ESD damage with the naked eye, but it literally blows ‘holes’ through circuit boards on a microscopic level. If we expose a board to ESD, it can be very hard to diagnose properly. The blame often is placed on software, or hardware, or incompatibility. Very few blame ESD, which can often be the culprit.
(For more ESD Fundamentals, visit https://www.esda.org/about-esd/esd-fundamentals/)
-Matt Haywood, General Manager of ReVamp Electronics