How does ESD Affect Your PCB Board?
Electrostatic discharge (ESD) occurs when two objects with different charges get close enough, or charged enough, to break down the dielectric between them.
Any PCB may be subject to an ESD if it’s touched or comes close enough to people, packaging, cables, furry pets, or any other object that might contain an opposite charge. When they do touch, that voltage discharges and creates a comparatively massive voltage spike. As the voltage spike dissipates, the discharge current generates electromagnetic fields across the PCB. The goal of ESD protection is to minimize any impact or effects from the discharge.
In particular, many modern chipsets are made using such small lithography features that they have little or no tolerance for high voltage, even direct current values above their operating voltage of 3.3V. The result of an ESD event directly reaching one of these components is usually disastrous, completely ruining the integrated circuit.
Nearly every element of your PCB design (traces, routing, layers, component placement, and spacing) can affect the ESD protection on your board. That means you need to consider ESD early in your design process; otherwise, you’re likely to require major PCB redesign to fix routing and component placement issues.