Conformal coating is the industry term for appling a specialised resin based coating to assembled circuit boards. Conformal coatings form a thin dielectric polymeric film which ‘conforms’ to the contours of a PCA to protect it from harsh environments.
Conformal coating can be used to;
For specific strengths and benefits of coatings please see the more detailed page on types of conformal coating.
As well as providing protection against ingress and the electrical protection, conformal coating works like a protective barrier physically holding the components to the board, which provides another level of protection for electronics where thin or flexible boards are used or where the boards can be subject to vibration and kinetic stresses.
|Dip Coating||Spray Coating|
Conformal coatings are often confused with lacquers and varnish that are used for protection of wood and metal. A conformal coating used to protect PCA’s needs to have a wider temperature range than lacquers/varnish ranging between -60°C to 150°C and above.
Printed circuit protection using conformal coatings has been around for over 60 years and is even more important today with the ever increasing component density and decreasing track widths, where in the past a conformal coating was a nice to have it is now a must have to protect your product from harsh environments.
The application of conformal coatings has come a long way over the last 60 years with automatic dip systems and selective coating systems now being the norm for high volume production, but hand spray still has its place for low volume coating applications.