Tiny bursts of energy

Static electricity: an old phenomenon but now more problematic than ever

By Claire Marchand

Static electricity has been a serious industrial problem for centuries. As early as the 1400s, European and Caribbean forts were using static control procedures and devices to prevent electrostatic discharge ignition of black powder stores. By the 1860s, paper mills in the USA employed basic grounding, flame ionization techniques, and steam drums to dissipate static electricity from the paper web as it went through the drying process.

Nanochip
Contact with the slide has charged the child's hair positively so that individual hairs repel one another (Photo: Chris Darling)

Today, as devices have become faster and smaller, their sensitivity to electrostatic discharge (ESD) has increased. Because electrical and electronic products contain many components, manufacturers want to be assured that the electronic components used in their products are of the required quality.

What causes electrostatic discharge?

ESD happens because of a build-up in static charge caused by friction. When certain surfaces move against each other, electrons rub off one surface and accumulate on the other, causing a difference in potential electrostatic energy to build up between the two.

The accumulated voltage may reach a point where it is powerful enough to jump very quickly to another surface holding a different level of static charge. This jump or discharge causes the feeling of pain when the skin is one of the surfaces.

ESD shouldn't be taken lightly

Static electricity can cause product damage, product malfunction and provoke shocks when it discharges. It can cause other problems by attracting dust and lint. As a consequence, ESD can cause poor production yields and unreliable product performance.

As smaller electronic devices such as NEMS (nanoelectromechanical systems) and MEMS (microelectromechanical systems) are used increasingly by the electronics sector, it becomes very important to understand and control electrostatic phenomena. Because of their size, these tiny electronic components can become permanently damaged even by very low electrostatic discharges.

Because electrical and electronic products contain many components, manufacturers want to be assured that the electronic components used in their products are of the required quality.

Protection from ESD by IEC...

This is why it is essential for industry to put in place protection programmes against ESD. IEC is the world reference for ESD standards. This is where the IEC, through its standardization and Conformity Assessment (CA) activities, plays a major role.

The IEC 61340 series of International Standards on electrostatics covers measurement methods in electrostatics; methods for simulating electrostatic effects; standard test methods for specific applications; and protection of electronic devices from electrostatic phenomena.

...and IECQ

IECQ, the IEC Quality Assessment System for Electronic Components, offers assessment and Process Approval Certification as a means of providing independent verification of compliance to the IEC 61340 series for facilities handling unprotected ESD sensitive devices.

As semiconductor devices continue to become more sensitive to ESDs it is important that companies handling these devices develop, implement and maintain effective ESD control programmes in their facilities.

The IECQ ESD AP (Approved Process) Scheme is also designed to work with a company’s existing quality management system. Companies with electrostatic discharge requirements may instil confidence; however, experience has shown that an approach on the management and control of ESD is necessary.

Gallery
Static on the playground Contact with the slide has charged the child's hair positively so that individual hairs repel one another (Photo: Chris Darling)
Nanochip Tiny electronic components can be permanently damaged by ESD
printed electronics Static shielding bags are the first line of defense in the fight against ESD (Photo: Lexicon Technologies)