While we can occasionally feel some of these effects, static electricity is normally present at a lower level that we cannot feel, hear or see, but enough nevertheless to damage sensitive electronic components. It can build up rapidly on objects to produce surprisingly high voltages.

​

If two objects that have different voltages approach each other closely enough, a spark of electricity may jump from one object to the other in a fast electrostatic discharge.

​

While it only lasts a microsecond or less, the peak discharge current can be several Amps and the peak power can be in the kilowatt range! – More than enough to fry a silicone chip.

​

Lightning is a very dramatic version of Electro Static Discharge, but it helps to highlight the high energy involved.

Why worry about it?

ESD can cause unseen damage to electronic components during the manufacture of electronic assemblies and equipment. If the damaged component fails immediately, it can result in a board which fails tests and requires rework. This represents lost production and additional manufacturing costs.

​

Worse than this, a component may be partially damaged and weakened. It may suffer a change or drift in characteristics. It may remain within specification, but fail later when in use by a customer. It has been estimated that 90% of damaged devices may be discovered in this way. This is the most expensive type of failure, as it represents: