The cost of static-related damage can be huge, but creating safe work areas will cut losses and reduce failure rates. Here, Phillip Fowler highlights the potential cost savings to be made by minimising electrostatic discharge and outlines the areas where action can be taken.

Independent research shows that a major technology company's estimated cost for static-related damage was millions of dollars but after embarking on an electrostatic discharge (ESD) control programme $5 million was saved in the first year - a 3000 per cent return on investment. Other research substantiated that 70 per cent of failures in electronic devices can be attributed to static damage from people who are incorrectly grounded.
Static-safe work areas will drastically lower these losses and failure rates. These areas use materials and equipment that limit electrostatic voltages and ESD. In Europe equipment used to create an EPA should comply with the requirements of BS IEC 61340-5-1 and should be monitored by an ESD co-ordinator.
Eight main components are required for an EPA, assuming the existence of a suitable workbench.
* Tablemat to provide a work surface that dissipates static from conductive items placed on it.
* Common ground cord to connect the tablemat and one or two wrist straps to ground.
* Wrist strap and coil cord to connect to the wearer's skin to ground via a coiled cord.
* Floor mat to provide a surface that dissipates static charges from conductive items placed on it.
* Floor mat ground cord to connect the mat to ground through the common ground socket.
* Heel strap or sole grounder to connect the walking or standing person to ground. It is mandatory to wear these on both shoes.
* Constant monitor to check that the path to ground is connected and working properly.
* ESD awareness sign to alert personnel to keep to the control procedures set up by the ESD co-ordinator.
An EPA ground point should provide a low resistance path (<2 ohms) to ground, usually to mains protective earth. Furthermore ground-bonding points must be provided next to each workstation for wrist strap connection and should be clearly marked; there should also be sufficient points to provide for operators and visitors. The points are connected to ground through a resistance of up to 106ohms.
Moving components or assemblies from one EPA to another needs caution. One option is to use a static shielding bag to prevent ESD damage. Alternatives are ESD safe boxes or tubes and in all cases the packaging should be clearly labelled to indicate its purpose. Items that regularly move across an EPA boundary should be marked with an ESD caution label.
Having set up the EPA the user must also implement a series of regular maintenance and operational checks, and continuity of the correct wiring and connection methods for the various static control components must be ensured. Even all non-essential plastic items (cups, food containers etc.) should be removed from the workstation because they can generate harmful static charges.
Good static control practice can more than recover its return on investment through reduced failures; but it will provide even higher returns when reputation is taken into consideration. If a product fails because of ESD damage during production testing it is a nuisance to say the least; if it fails when it reaches the customer it is a problem; but if it fails in service it is a potential catastrophe and the cost of this would be at least one thousand times that of an in-house failure - customer dissatisfaction, lost business, even lost jobs.

ENQUIRY No 21

Phillip Fowler is managing director, Static Control Components (Europe) Ltd, ESD Products Division, Reading, Berkshire, UK. www.staticcontrol.com