Q. What is the best way to protect a printed circuit board (PCB) from ESD?

A. Plenty of ESD solutions are available, but there simply isn't a single best way. ESD is pervasive. Damage can occur during rework, automated handling, or transport. Finding the best solutions requires recognizing the problems, then selecting the best methods to solve specific problems.

However, in designing and implementing effective ESD control programs, it is possible to identify a simple and focused solution. By concentrating on just four basic concepts, the task of static control can become more manageable.

First, design products and assemblies to be as immune from ESD as is reasonable. Use fewer static-sensitive devices whenever possible. For those ESD-sensitive items that must be used, provide appropriate input protection on devices, boards, assemblies, and equipment. The more ESD control built into product design, the fewer problems there will be.

Second, concentrate on eliminating or reducing the generation and accumulation of electrostatic charge in the first place. Get rid of as many static-generating processes or materials (such as common plastics) as possible from the work environment.

Third, dissipate or neutralize electrostatic charges by grounding dissipative or conductive materials in the environment or by using ionization on common plastics or other insulators.

Finally, prevent electrostatic discharges that do occur from reaching susceptible parts and assemblies. Grounding or shunting devices and assemblies will carry any discharge away from the product. Another method is the packaging, handling, and transporting of ESD-sensitive devices and assemblies in proper packaging and carriers.

Nearly all static control efforts can be simplified into one of four basic concepts:

These four guidelines form the basis for effective static control programs and simplify the selection of appropriate materials and procedures. In most circumstances, effective programs involve all of these concepts. No single procedure or product can do the entire job.