What is the difference between catastrophic and latent ESD damage?

Catastrophic damage fails immediately at test; latent damage reduces the part margin and fails months later in the field. Latent failures are the dangerous case because they pass final test and are invisible in inspection.

Why do packaging and handling matter as much as the bench?

Because most discharges happen away from the bench: in stores, during transport or when a board is handed to someone without a ground. Protected packaging, grounded carts and training matter as much as wrist straps at the station.

Blog

ESD in PCB Assembly

A discharge too small to feel can degrade a junction. The damage is often latent and shows up as a field failure.

Hitech Circuits Engineering Desk

Shenzhen, China · PCB fabrication and assembly

2 min read

Published: 2018-08-15

Last updated: 2026-10-18

Technical review: Process figures checked against our published capability sheet. View capability sheet

Electrostatic Discharge and Its Effect on PCBs- Advanced PCB Assembly-Hitech PCB

What ESD does

A fast current pulse through a semiconductor thin oxide or junction can melt a small volume of silicon. The result is either an immediate open or a weakened part that drifts out of specification later.

Where it enters

Receiving and stores, when bags are opened
Manual handling of boards and trays
Soldering and rework stations
Test fixtures and cable handling

Controls

Ground the operator, the bench and the tools; use dissipative packaging; verify wrist straps daily; keep ionisers where insulators cannot be grounded. Document the programme, because a good EPA is a routine, not a purchase. A documented, daily-verified EPA is also the minimum to ask about when auditing pcb assembly services.

Technical Specifications

Typical control target: EPA with wrist strap and grounded mats
Sensitive parts: MOS, LEDs, sensors, fine-geometry ICs
Acceptance: IPC-A-610 workmanship

Frequently Asked Questions

What is the difference between catastrophic and latent ESD damage?
Catastrophic damage fails immediately at test; latent damage reduces the part margin and fails months later in the field. Latent failures are the dangerous case because they pass final test and are invisible in inspection.
Why do packaging and handling matter as much as the bench?
Because most discharges happen away from the bench: in stores, during transport or when a board is handed to someone without a ground. Protected packaging, grounded carts and training matter as much as wrist straps at the station.