What is a Conformal Coating?
Conformal coating material is a thin polymeric film which aims to protect vital electronics from corrosion or failure caused by exposure to harsh/wet environments or contamination. In addition, they can protect circuits and components from abrasion and solvents. Stress relief is also provided, as well as protection of the insulation resistance of the circuit board.
Conformal coatings are traditionally applied by dipping, spraying or simple flow coating, and increasingly by select coating or robotic dispensing. Most circuit board assembly houses coat assemblies with a layer of transparent conformal coating rather than potting. The use of such coatings have a long and important history in the military and medical space, as both industries have been in better positions to absorb the cost of applying such protective coatings to mission critical electronics.
The conformal coating space can be classified into five material categories: acrylics, polyurethanes, epoxies, silicones, parylene. Each of these materials has its own set of with pros and cons for application, usage and performance, and most have a place within certain industry segments that may make it more applicable and usable than in others.
Over the past several years, there have been great strides to make conformal coatings more accessible to electronics manufacturers in a wide range of industries, including consumer devices like smartphones, wearables, tablets, eReaders and audio.