An ESD safe workspace is only as good as its weakest link. Any vulnerability within an ESD sensitive environment could create a breach in an electrically conductive chain. Here are answers to frequent questions about creating effective and safe ESD workstations.
Do I need an ESD Mat if I have A Grounded Workstation?
When using an ESD mat on a grounded workstation, grounding the ESD mat is not essential. However it’s not 100% safe. As we explain below, any damage to the ESD mat or dust/residue on the surface could compromise its electrical properties. For example, a ESD mat connected to the workstations ground nut. Or, it could have its own wire from the snap to its own ground.
Sometimes, ground wires fail. And unless you’re testing and monitoring the static properties of your workstation daily, one might not discover a faulty connection before damage occurs to a device. That’s why having independently grounded devices is preferred, but not required. The most safe option is to use independently grounded sources.
Possible problems when not grounding an ESD mat.
ESD work surfaces provide a permanent solution to portable ESD mats.
Use of an ESD mat on an ESD work surface is not required, but ESD working surfaces should always be grounded to a common ground point, and never daisy chained.
A number of factors lead to the degradation of ESD mats, including dragging heavy objects over the surface, abrasion or cuts, chemical cleaners, or direct heat caused by soldering or rework. Additionally, the most common precursor to ESD events is not faulty equipment, but instead operator error such as setting sensitive devices on non-ESD surfaces or failure to follow proper grounding procedure. ESD benches provide a permanent stand in for ESD work surfaces and reduce the likeliness of user-driven ESD events, such as hastily setting down an ESD device on a non-ESD workstation. Regardless, the soft properties of rubber ESD table mats provide a soft surface for electronic components that may be damaged by subtle or repeated impact on a work surface.
When Do You Need an ESD Wrist Strap?
Typically, ESD wrist straps are the primary means of grounding personnel. When properly worn and connected to ground, a wrist strap keeps the person wearing it near ground potential. Because the person and other grounded objects in the work area are at or near the same potential, there can be no hazardous discharge between them. In addition, static charges are removed from the person to ground and do not accumulate. When personnel are seated on a chair which is not EPA appropriate, they are to be grounded using a wrist strap. –ESDA.org
