WHAT IS CONFORMAL COATING?
Conformal coating is a protective non conductive dielectric layer that is applied onto the printed circuit board assembly to protect the electronic assembly from damage due to contamination, salt spray, moisture, fungus, dust and corrosion caused by harsh or extreme environments.
WHAT IS POTTING?
Potting (embedment) is the covering of an electronic or electrical device to protect it from the surrounding environment. The potting method uses a "pot" or case or shell to put the device in and then pour the liquid potting compound to the top of the case covering the device and completely encasing it. The case becomes part of the finished unit. This is the most common method used, especially for high speed and many-units-per-hour production-line conditions.
SHOULD I USE CONFORMAL COATING OR POTTING?
Typical projects that use potting instead of conformal coating would be circuit boards that are going to be facing potential impact damage or rough mechanical abrasion. Depending on the type of potting compound, potting is a very clear choice for impact resistance.
Conformal coatings are a more popular choice than potting for good reason. If you would ever need to rework your assembly or have any sort of thickness or weight restrictions, conformal coating would be your best bet. Conformal coating is very easy to inspect, as well as rework deficiencies in. Potting does not offer the flexibility that most contract manufacturers demand in a protective finish.