Polymeric Layers volume 85

Polymeric Layers volume 85 - Praca Zbiorowa

A conformal coating is a thin polymeric layer applied onto a PCB or other electronic substrate by brushing, dipping, spraying or simple flow coating, and increasingly by select coating or robotic dispensing as the last processing step. The coating provides a barrier which protects the PCB or other electronic substrate (conductors, solder joints and components) from moisture, oxidation and other environmental and mechanical attacks during service life of the product, significantly extending the life of the components and circuitry. Conformal coatings are available in a number of different chemistries which include PU (solvent and non-solvent versions), silicones, epoxies, acrylics, acrylated urethanes and parylenes. The choice of coating depends on the chemical and mechanical (abrasion) resistance required, the degree of rework envisaged, and the method of curing.