Anyone using, handling, storing or transporting electronic components will know that potential damage from electrostatic discharge can be a major problem. What makes the issue particularly difficult is that damage can escape detection during quality control inspections and components appear to work normally, only to fail later. Avoiding this is key to ensuring a product’s quality and reliability, while also minimising returns, reducing warranty costs and keeping customers satisfied.
The solution is to adopt measures known to prevent ESD during component manufacturing, testing, shipping and handling. By following correct practices, it’s relatively straightforward to create an ESD-safe environment where sensitive devices are protected from damage.
To the uninitiated, the vast range of electromagnetic compatibility products from suppliers such as Multicomp Pro, Desco, SCS, Menda, Emit and Simco-Ion can be bewildering, so the remainder of this article provides readers with a guide to their options and the benefits they offer.
Anti-static bags such as the zip-top resealable units from Multicomp Pro are designed to incorporate a static dissipative coating which prevents static build-up on the bag’s surface, protecting the product inside. RoHS-compliant bags are formed using blow-moulded polyethylene with anti-static additives and are developed to dissipate a static charge to ground, preventing static charge building up on the package or device. Also, the material will not charge when rubbed against other materials.
Another essential product is a one size fits all anti-static wrist strap from Multicomp Pro that grounds users so that static electricity cannot build up on their body. The product is RoHS-compliant and comes with an adjustable strap, coiled 1.8m earth lead and spring-loaded 10mm press studs for a secure and comfortable fit.
For workers on the move, ESD toe and heel grounders from SCS come with a two-layer sole capable of being repositioned. Ideal for high-volume use, the grounder also has a 457mm conductive ribbon which provides a continuous path-to-ground so electrostatic charge is removed from the body.
Protection can be improved further by using two-layer bench mats: Multicomp Pro’s ESD bench matting disperses electricity through anti-static (conductive) and static-dissipative materials with synthetic rubber. Available in green or grey, the mats neutralise ESD by causing it to flow at a slower rate across the surface of the mat.
Other options include: Desco’s earth bonding plug which provides a common ground point for ESD workstations by replacing live and neutral pins with insulated plastic pins; and Raaco’s stackable anti-static ESD bin which is made from conductive plastics to dissipate electrostatic charge and prevent static build-up, reducing static while components are in storage.
To control static charge in mini-environments, suppliers such as Simco-Ion and Emit offer a range of ionizers including ionizing air bars, bench top ionisers and overhead ionizing air blowers, air guns and nozzles. The use of ESD air ionizers in electronics work areas removes build-up of potentially damaging static charges. Ionizers deliver a balanced stream of positive and negative ions and are used primarily to control static charges on insulating materials such as standard plastic. Ionizers protect electronic devices from electrostatic potential that ESD wrist straps and table mats just can’t eliminate.
Farnell’s ESD portfolio contains around 2,000 products, available for same day despatch. Farnell customers can also access 24/5 technical support and free access to online resources, data sheets, applications notes, videos and webinars.