Conformal coating

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Conformal coating is a protective, breathable coating of thin polymeric film applied to printed circuit boards (PCBs). Conformal coatings are typically applied with 25–250 μm^[1] thickness on electronic circuitry to protect against moisture and other substances.

Coatings can be applied in many ways, including brushing, spraying, dispensing, and dip coating. Many materials can be used as conformal coatings depending on manufacturer needs, such as acrylic, silicone, urethane, and parylene. Many circuit board assembly firms apply a layer of transparent conformal coating to assemblies as an alternative to potting.

Conformal coatings are used to protect electronic components from possible environmental exposure; they allow moisture to escape but protect against contamination. More recently, conformal coatings are being used to reduce the formation of whiskers^[2] and to prevent current bleed between closely positioned components.