Dendrites on PWBs: Formation, Risks, and Prevention Strategies
In today’s Ask Dr. Adam video, he’ll define dendrites and explain how they can cause significant damage to printed wiring boards (PWBs). Dendrites are electrochemical migrations that form when moisture is present between biased traces, creating a pH gradient that strips metal ions from one electrode and plates them onto another. The resulting root-like conductive paths can lead to leakage currents, short circuits, and even fire hazards.
Dr. Adam explains how dendrites pose a unique challenge by developing over time and evading initial testing, and how to prevent their formation. He covers surface insulation resistance (SIR) tests that can detect early signs of dendrite growth, and how conformal coating serves as an effective moisture and diffusion barrier, significantly slowing dendrite formation.
By understanding dendrite formation and implementing proper cleaning and coating techniques, engineers can protect their PWBs from these pesky plagues, ensuring better long-term performance and reliability of electronic devices.