What is ESD?
Electrostatic discharge (ESD) is the sudden and momentary flow of electric current between two objects caused by direct contact, or an electrostatic field. The term is used in the electronics industry to describe momentary unwanted currents that may cause damage to electronic circuits & components.
ESD is a serious issue in solid state electronics, such as integrated circuits and steps must be taken to prevent it. Semiconductor materials such as silicon can suffer permanent damage when subjected to high voltage; as a result all products and equipment used during the assembly or inspection of PCB boards should prevent and protect from ESD.
What causes ESD?
One of the causes of an ESD event is static electricity. Static electricity is often generated when two materials are brought into contact and then separated. Examples include walking on a rug, rubbing plastic comb against dry hair, ascending from a fabric car seat, or removing some types of plastic packaging. In all these cases, the friction between two materials results in static being created, thus creating a difference of electrical potential that can lead to an ESD event.
Another cause of ESD is through electrostatic induction. This occurs when an electrically charged object is placed near a conductive object isolated from ground. An ESD event may occur when the object comes into contact with a conductive path.
For example, removing a styro-foam cup from a stack of cups can create a charge potential on the surface of the removed cup as it separates from the stack. If this cup is then closely placed next to an integrated circuit, the charge potential on the cup can sweep across the chip’s exposed conductors, causing damage to the internal silicon circuit. The damage may be so minor that the chip is merely weakened rather than outright destroyed, and it will appear to function normally in some cases but not others. It could fail in the future without warning.
How to prevent and protect against ESD
The best way to prevent ESD damage is to work in an Electrostatic Protective Area (EPA). An EPA can be a small working station or a large manufacturing area.
The main principle of an EPA is that there are no highly charging materials in the vicinity of ESD sensitive electronics, all conductive materials are grounded, equipment such as work benches and lamps are grounded, workers are grounded, and charge build-up on ESD sensitive electronics is prevented.
ESD prevention within an EPA may include using appropriate ESD-safe packing material, the use of conductive filaments on garments worn by assembly workers, conducting wrist straps and foot-straps to prevent high voltages from accumulating on workers’ bodies, anti-static flooring materials to conduct harmful electric charges away from the work area, and humidity control.
Manufacturers and users of integrated circuits must take precautions to avoid ESD. Prevention is the best way to avoid costly ESD damage.
ESD & Clean Rooms
A clean room is a controlled environment where products are manufactured. It is a room in which the concentration of airborne particles is controlled to specified limits. These contaminants are generated by people, process, facilities and equipment and they must be continually removed from the air before they settle on any surface.
Electrostatic fields attract dust particles to surfaces and once settled they cannot be removed by extraction systems. Products with special ESD coatings are particularly suited for use in clean rooms because they stop the build-up of electrostatic fields and prevent the attraction of particles.
Daylight ESD Safe range of lamps and magnifiers
Our range of ESD safe lamps & magnifiers provide full protection against static electricity and electrostatic discharge (ESD).
The entire lamp (head, lens, joint and arm) is grounded and has special static dissipative materials and coatings to smoothly take away static charges in a controlled manner, preventing any build-up of static electricity which gives complete protection against ESD damage.
Our products are independently verified to be suitable for use in EPA (Electrostatic Protected Areas – IEC 61340-5-1 and ANSI/ESD 20:20)
They can also be used in clean rooms because the special static dissipative materials and coatings stop the build-up of electrostatic fields and prevent the attraction of particles.
Our lamps and magnifiers are designed and engineered to offer high quality light with the best possible field of view and optimally performing ergonomics. We use carbon fibre and special conductive coatings on all our ESD models.