Electrostatic discharge damage is quiet: the module electronics that failed in the field passed every test on the line. A working ESD program is mostly discipline, and it is cheaper than the failures it prevents.
Define the protected area honestly
An ESD protected area is a boundary with rules, not a sign on the wall. Mark where it starts, control what crosses it, and make the entry routine — wrist strap test, footwear check where floors are part of the concept — fast enough that people actually do it every time.
Ground the things that move
Workbenches and mats get grounded once and stay put. Carts, trays, fixtures and chairs move, and every movable item is a chance to carry charge to a connector. Standardise on dissipative materials for anything that touches modules, and check continuity on a schedule, not on suspicion.
Watch the process, not just the people
Peeling protective film, unwinding tape and separating foam inserts generate charge next to the most sensitive components on the line. Ionisation at those stations, verified periodically with a charge-plate monitor, addresses the sources wrist straps cannot reach.
Audit with measurements, not memory
A monthly walk with a surface resistance meter and a field meter finds the failed mat, the painted-over ground point and the new chair that arrived without anyone asking. Log the readings — trends catch degradation before it becomes a batch problem.
