PCB conformal coating is a thin polymeric protective film (25–250μm thick) applied to printed circuit boards to shield them from environmental hazards while maintaining electrical functionality. It conforms closely to the PCB’s contours, acting as an invisible barrier for sensitive components and solder joints.
Its core functions include protecting against moisture, dust, chemical contaminants and salt spray, preventing short circuits and corrosion, enhancing electrical insulation, and reducing mechanical damage from vibration. It also helps inhibit tin whisker formation and electrochemical migration in high-density PCBs.
Common types include acrylic (cost-effective, easy to rework for consumer electronics), silicone (excellent temperature resistance for aerospace and automotive use), polyurethane (high chemical resistance for harsh industrial environments), and parylene (ultra-thin, pinhole-free for high-reliability devices like medical implants).
Applied via brushing, spraying, dipping or selective coating, it is widely used in automotive, aerospace, industrial and consumer electronics, significantly extending PCB lifespan and reducing failure rates in harsh conditions.
