Making the correct choice of floor system, when establishing an electrostatic protected area (EPA), is essential to ensure that sensitive electronic components and assemblies are adequately protected from the harmful effects of electrostatic discharge (ESD).
But with all these EPAs, ESDs, ANSIs and BVGs, it can become quite confusing quite quickly! Below AllThingsFlooring.com has pulled together a glossary of flooring terminology to make static control surfaces simple!
This is a term used to describe materials that prevent the buildup of static electricity. Both conductive and dissipative materials are classified as ‘Antistatic’. Insulative materials are not.
The electrical charge caused by an imbalance of electrons on the surface of a material. This electrical charge remains until it either flows into the ground, or loses its charge quickly through a discharge. Flooring surfaces charged with static electricity attract dust and other contaminants that can damage sensitive electrical components.
Electrostatic Discharge (ESD):
Electrostatic discharge (ESD) is the immediate release of static electricity when two objects come into contact. ESD can damage sensitive electronic components, causing equipment to malfunction or fail. As such ESD control procedures, including footwear, mats and specialist floor coatings, are put in place to ensure electrostatic charge goes into the ground instead of into the device.
Triboelectric is a type of contact electrification on which certain materials become electrically charged after they come into frictional contact with a different material. Rubbing glass with fur, or a plastic comb through the hair, can build up triboelectricity.
Body Voltage Generation (BVG):
Body Voltage Generation or BVG is the best indicator of the amount of static electricity generated by a person walking on the floor as well as floor’s effectiveness in controlling it.
When a charge can be conducted through a material, the solution to static discharge problems is to provide a path for the charge to flow to ground, thereby neutralising it. This solution works only for static dissipative and conductive materials.
An electrical conductor is a substance in which electrical charge carriers, usually electrons, move easily from atom to atom with the application of voltage. Conductivity, in general, is the capacity to transmit something, such as electricity or heat.
Conductive materials have low electrical resistance, and static charges can flow easily across its surface. These materials generally have less than 1 x 105 ohms surface resistance.
Dissipative materials allow charges to flow through the material, but slowly and in a much more controlled manner than with conductive materials. Dissipative materials will control and slow the charge, dissipating it as heat. These materials have between 1 x 105 to 1 x 1012 ohms surface resistance.
Insulative materials prevent or limit the flow of electrons across their surface or through their volume. Insulative materials have a high electrical resistance and are difficult to ground. Static charges remain in place on these materials for a very long time. Anything with a surface resistivity greater than 1 x 1012 ohms is considered to be insulative.
The instrument used to test resistivity on the floor. It applies a 100-volt charge to the surface of the floor and will give you a reading in ohms that will determine whether the floor is in the conductive, dissipative or insulative range.
HBM (Human Body Model):
The human-body model (HBM) is the most commonly used model for characterizing the susceptibility of an electronic device to damage from electrostatic discharge (ESD). The model is a simulation of the discharge, which might occur when a human touches an electronic device.
ANSI/ESD S20.20 is the multi-industry standard for the development of ESD control programs that protect today’s increasingly sensitive electronic components, assemblies, and equipment from costly ESD damage and reduce downtime. Using the standard’s control methods and guidance, an organization can develop an ESD control program that protects devices down to 100v (class 1a) or less.