What is ElectroStatic Discharge (ESD)?

What is ESD (ElectroStatic Discharge)? How could it affect my Hardy Instrument?

Electrostatic Discharge, or ESD, is a single-event, rapid transfer of an electrostatic charge (energy) between two objects, usually resulting when two objects at different electrical potentials come into direct contact with each other. ESD can also occur when a high electrostatic field develops between two objects in close proximity. ESD is one of the major causes of device failures in the semiconductor industry.

Everyone remembers a time when they walked across a carpet, touched a doorknob and received a shock. That is ESD and it is a natural event that can seriously damage your expensive electronic equipment..

Electrostatic charge build-up occurs as a result of an imbalance of electrons on the surface of a material. Such a charge build-up develops an electric field that has measurable effects on other objects at a distance. The process of electron transfer as a result of two objects coming into contact with each other and then separating is known as 'triboelectric effect'.  Rubbing two ballons together and they stick to the wall and make your hair stand up.

This charging process results in one object gaining electrons on its surface, and therefore becoming negatively charged, and another object losing electrons from its surface, and therefore becoming positively charged. A person can get triboelectrically charged in a number of ways, even by just walking across a room.

ESD related failures manifest themselves in a number of ways, exhibiting one or more of these attributes: junction leakage, short, or burn-out; dielectric rupture; resistor-metal interface rupture; resistor/metal fusing; and die surface charging.

To eliminate ESD, everything in your workplace, from equipment to work tables to cabinets and racks, must be connected to a common ground. If your facility uses conductive flooring, then this should also be connected at regular intervals to the common ground. Having a single or common ground will ensure that everything in your facility will remain at the same potential. Any charge build-up will immediately be dissipated by a good grounding system. The use of properly grounded wrist and foot straps or conductive shoes will also fall under this category, since these will bring any charge build-up on personnel to the common ground. Examples of personnel grounding accessories include wrist straps, sole grounder, and conductive shoes

Control of Relative Humidity is also important, since the moisture in the air acts as a conductive path that can bring static charges to the common ground. Thus, a very dry environment is inviting ESD, but remember that excessive humidity might trigger corrosion. As the humidity changes at your facility you will see different levels of ESD. A majority of our Tech Support calls at certain times of the year are due to our customers experiencing equipment instability and component damage that is caused by ESD buildup. It is critical to have an effective grounding system to allow a safe discharge path.

Proper training of personnel on ESD precautions is critical to reduce or eliminate ESD damaged electronics. A good ESD control program should incorporate a training scheme that will ensure that everyone is aware of the company's ESD controls and Standard Operating Procedures. A regular audit for ESD control compliance is important.

To protect your Hardy controller from ESD damage please read WebTech answer ID918 "How can I protect my controllers, systems and scales from static electricity problems?"