Why ESD Control Flooring is Essential for Electronics-Related Industries, and How it Works
by Peter Collins - Sales Representative for Texas
“If you don’t have time to do it right, when will you have time to do it over?”
- John Wooden
Most drivers don’t need to know the technical details of how an internal combustion engine works in order to competently operate a vehicle. They just have to: know the rules of the road, develop good driving skills, identify reputable vehicle manufacturers and service shops and match their needs to the different options available when it comes time to buying a vehicle. In other words, the owner’s responsibility is limited to the operation and maintenance of the vehicle.
Similarly, most professionals responsible for ESD control measures at their respective companies don’t necessarily need to know the intricacies of how every element they’ll use works to minimize the negative effects of ESD events. But, because static build-up and discharge can cause injury to human life and damage to property, components and finished products, it’s important to understand the effects of ESD in the workplace and how to eliminate them as potential threats to products, property and personal safety. It’s also important to know where to turn and who the reputable suppliers are when implementing an effective ESD control program.
A comprehensive ESD control program should take into consideration the ESD environment as a whole, including packaging materials, work stations, clothing, wrist and foot straps, etc. But because the ESD flooring surface represents the single biggest area related to ESD protection in the workplace and virtually all other elements come into contact with the floor, we’ll focus specifically on the benefits of seamless, traffic and chemical-resistant ESD flooring from Arizona Polymer Flooring (also see Pros and Cons of ESD Flooring Options )
What is ESD and Why Is It Important to Electronics-Related Industries?
Let’s start with defining what electrostatic discharge (ESD) is. In his article on mitigating electrostatic discharge, APF Technical Director Jim Essig explains that ESD “is the sudden spontaneous transfer of electric current. Basically a charge flows through a spark between two bodies at different electrostatic potentials as they approach one another.” His article goes on to point out that “jet fuel (and gas) under proper conditions can ignite with a 1,000-volt charge, hence all the warning signs at your local gas station. But the real danger is to today’s sophisticated electronic devices. These can be damaged by as little as 25 volts.” As a comparison, it takes about 3,500 volts of electricity for a person to feel a static shock.
Static charge can be generated and built up by walking across a floor, brushing our clothes with our hands or by simply sitting then standing. If a discharge is powerful enough, catastrophic damage to an electronic device or its components will be visible. However, because latent failure can occur at much lower voltage ranges it’s far more difficult to detect. Latent failure in electronic devices is responsible for an estimated 90% of all failures in those devices. It’s further estimated that ESD damage costs American industry $5 billion dollars every year.
Studies of damage to components in electronic devices, related to ESD events, estimate the cost of damage according to when the event is detected. If the damage is discovered at the point of assembly, the cost is one times the cost of assembly and labor. But if damage is discovered during QC testing, the cost is ten times that of assembly and labor. And if the damage is discovered once the device reaches the customer, the cost is100 times the cost of assembly and labor. (Source of cost estimates: Cisco Systems, Inc.).
How ESD Flooring Works
There are two generic types of ESD floor treatments: conductive and dissipative. The main distinction between an ESD conductive floor treatment and a dissipative one is that conductive flooring has lower resistance to electrical flow and dissipative flooring is more resistant to the flow of electrical current.
In a work environment, personnel, machinery, tools, components and fabricated products all interact and that interaction will cause electrostatic discharge, often but not always, visible as a spark. In addition to these, chemicals, gasses and fine powders can be ignited by the release of a static charge. Again, electrostatic discharge occurs as a result of friction between two materials, caused by contact and separation of the materials. ESD floor coatings and coverings are made to limit static build-up in people and objects and to quickly remove a charge on people and equipment.
What Industries Need ESD Flooring?
Because static electricity is the cause of significant damage and injury to products, property and personnel every year, it’s critical that any and all ESD susceptible areas undergo evaluation of any existing or potential threat from the effects of ESD. Many industries require ESD protection and as our dependence on electronics grows, the need for ESD protection grows with it. Following are some examples of industries with existing ESD flooring needs:
- Aerospace and avionics
- Automobile Class-0* manufacturing
- Chemical plants
- Computer data centers and server rooms
- Cosmetics industry
- Electronics manufacturing
- Hospitals and healthcare centers
- Laser and optical facilities
- Munitions and fine particle production plants
- Pharmaceutical industry
- Powdered foodstuffs manufacturing
- Semiconductor fabrication
* Term used to refer to devices with thresholds of less than 250 volts
What Standard is Used to Determine ESD Control?
ANSI/ESD S20.20-2014 Protection of Electrical and Electronic Parts, Assemblies and Equipment (Excluding Electrically Initiated Explosive Devices) is an industry standard developed by the ESD Association. It defines administrative and technical requirements for establishing, implementing, and maintaining an ESD Control Program to protect electrical or electronic parts, assemblies, and equipment that are susceptible to ESD damage from Human Body Model (HBM) discharges greater than or equal to 100 volts.
To measure the resistance levels of ESD conductive and dissipative flooring: ANSI/ESD STM 7.1. Measure the resistance to ground, resistance to groundable point and resistance point-to-point (or surface resistance).
It takes 3,500 volts of electricity for a human to detect a static electricity charge but only 1,000 volts to ignite gasoline fumes and as little as 25 volts can cause latent damage to critical components of manufactured electronic devices. Because the lack of ESD control in some work environments can have catastrophic consequences, a variety of different factors must be taken into consideration for an ESD control program to be fully effective, and the single most important of them is the workplace flooring.