How to Protect Life-Safety Equipment from ESD

As a manufacturer of fire-alarm monitoring devices, one of our most important efforts is to ensure our products are handled free from ESD (Electrostatic Discharge).

About six weeks ago, Digitize was purchased by new owners. That has led us to a thorough review and enhancement of our engineering, production, and testing procedures. We reviewed and improved ESD protections, and even the physical packaging protection of our central monitoring master server.

Let's review what is so bad about ESD, and how Digitize (and other manufacturers like us) minimize the risk to deliver a quality product.

Conductive ESD mats are used to prevent the buildup of static electricity on components being stored on the shelves. This reduces the chance of equipment damage caused by an electrical discharge.

What is ESD? And Why is it So Bad?

ESD (Electrostatic Discharge) is, by definition, a sudden and momentary flow of electric current between two electrically charged objects caused by contact, an electrical short or dielectric breakdown. The most common cause of ESD is static electricity. These electrical charges can weaken products without our knowledge and kill electronics.

ESD is a silent contributor to product failures. Here at Digitize, we do circuit board assembly and production. These circuit boards (PCBs) contain many tiny electric circuits and components that can be destroyed or "fried" with very small jolts of static discharge.

Much of this damage is only "partial", and cannot be detected during the quality control process. When a device encounters stress in the field, it's only then that the problem is discovered. At that point, it's your problem as the customer. That's unacceptable!

For any manufacturer, the only solution at that point is products being returned for repair. That means you lose time spent on RMA repairs instead of completing your project.

Ways to be ESD Safe

There are several methods of protecting against ESD that provide overlapping layers of protection. Each reduces the risk in its own way. When all are added together here at Digitize, our manufacturing process becomes nearly perfect from an ESD-protection perspective.

The Big Clean

Dust can be a big contributor of ESD. We just completed a big cleaning effort. The Stockroom, Shipping/Receiving, Assembly, Test and Production departments were all emptied, mopped, waxed, and restored! We began with the shelving, moved on to the table and bench tops, and finished with the floors.

Everything is clean and tidy, which makes the space more inviting and reduces the places where static can hide.

ESD Testers to evaluate our existing ESD defenses

Megohmmeter

Our megohmmeter test device measures electrical resistance on the Electrostatic Discharge Flooring. By placing two electrodes on the test flooring surface three (or more) feet apart, the megohmmeter lets know if our ESD Flooring is working to eliminate the static electricity properly.

Every room in our facility got a fresh coat of ESD wax, a good best practice that must be refreshed regularly. ESD Wax flooring acts as a conduit for the static charges a person makes while walking, and safely transfers them to a controlled ground point (the third prong on an outlet), through which the voltage potential is removed from the room.

Dual Wrist/Foot Strap Tester

The ESD tester is used to verify the ESD protective equipment is worn properly.

ESD Wristbands or Wrist Straps are safety devices that prevent the buildup of static electricity. They are worn by all employees that handle our circuit boards and their components. They are connected by a cord to the shelf, table, or work bench.

The new ones we have can be always worn, and the employee can go from shelf to workstation by just snapping and unsnapping to the attached cord. The Electrostatic Discharge wristbands we were using before needed to be put on and removed at each area of use.

As with the ESD Wristbands, ESD Shoe Straps also prevent the buildup of static electricity. They provide an effective ground for those walking around on ESD Flooring.

Employees need to test their foot straps a few times throughout the day by stepping on the ESD Test Station floor plate with one foot, while lifting the other. The green light "Pass" means they can begin working. The red light "Fail" means they are not protected from ESD and must wear a wristband while working. Of course, we tend to resolve this issue by using a new set of foot straps rather than using the less-convenient wristbands/straps.

ESD Matting for Table/Bench Tops

A work table with an ESD protective mat protects sensitive eletronics during assembly of our fire alarm monitoring devices.

Our Anti-Static Matting was tested and, when necessary, replaced on all work benches and tabletops. These are the surfaces where all kitting, assembly, production, and testing occur. The ESD matting prevents the sudden electrical discharge between electrically charged objects on contact.

ESD Blue Coats/Smocks

All employees engaged in handling circuit boards and their components are required to don the newly acquired Blue Smock. ESD/anti-static coats are designed to help with static discharge. They do not produce an electrostatic discharge and keep the wearer safe in static-prone environments. Electrostatic Discharge smocks can be tested using the same megohmmeter used for floors.

ESD Chairs

Our Electrostatic Discharge chairs are manufactured with ESD Fabrics, designed to protect from electrostatic discharges. The drag chains are used in conjunction with the ESD Flooring system. The chains ensure continuity from the chairs to the ground, providing an additional ground point.

ESD Copper Tape

Another added element to help prevent ESD are the strips of Conductive Copper Tape on the floor. It helps ensure the conductivity of the ESD Flooring system.

Although it's possible to achieve "adequate grounding" with enough square footage of ESD floor wax, it's obviously better if you can provide a true path to Earth ground. That's what copper tape does. You wax right over it on the floor, then it turns 90 degrees up the wall to the junction box of an outlet. That provides a connection to the grounding of the utility network.

Anti-Static Packaging Materials

Delivering a quality product is extremely important. After going through all the precautions to protect our products during assembly and production, it makes sense to continue protecting them through the shipping process.

Anti-static bags, bubble wrap, tape, pouches, and foam are all useful packaging materials to use while preparing our products for shipping. These do the same job as standard packing material of protecting against physical damage. Anti-static material, usually pink in color, is simply treated to reduce the risk of ESD damage.

No Eating at Workstations!

Common sense would dictate that eating or drinking at your workstation would be a "no-no". It's extremely important to keep all areas of circuit board assembly and testing, clean and dry, and free of extraneous debris.

Safe Walkways

Sometimes administrative support employees like me, who do not typically handle circuit boards or components, need to walk through one of these departments. It's beneficial to have walkways that are clearly marked with tape on the floor designated as "Safe" to walk through. This eliminates time spent putting on protective equipment simply to pass through an area.

Removal of Carpeting

Walking along carpeting is a major contributor of creating static electricity. Rugs are not a good fit for an electronics product manufacturer. Soon, all carpeting in our upstairs offices will be replaced with tile.

What's in store for the future?

We build you products with the highest quality, safe from Electrostatic Discharge, that will continue to satisfy your fire alarm monitoring needs for years to come. If you're a distrubutor, you can count on Digitize equipment to serve your customers reliably over the long term.

We continue to look for new innovative ways to manage ESD with new tools and testing equipment. Our engineers are hard at work with product redesign to alleviate potential ESD risk from customer handling.

Eventually, we will use increasing amounts of Surface Mount Technology (SMT) to improve the quality you receive, speed up our turnaround, and strengthen our relationship with you, our clients.

Please call us at 763-663-1011 or email info@digitize-inc.com to discuss your fire alarm monitoring project with a Digitize engineer.

Andrew Erickson

Andrew Erickson is an Application Engineer at DPS Telecom, a manufacturer of semi-custom remote alarm monitoring systems based in Fresno, California. Andrew brings more than 17 years of experience building site monitoring solutions, developing intuitive user interfaces and documentation, and...Read More