Due to the decrease in size of printed circuit boards (PCBs) and increase in packing density, there is a greater risk of shorts, corrosion of conductors and solder joints, dendritic growth and electro migration of metal between conductors.
Conformal coatings or thin polymeric films which “conform” to the surface of the printed circuit board (PCB) can improve the long term reliability of the assembly.
A conformal coating acts as an electrical insulator. It protects the electronic circuits from the environment including moisture ingress and contaminants such as airborne dust which could lead to corrosive effects and shorts. In addition, the use of conformal coatings protects circuits and components from abrasion and solvents. Stress relief is also provided for the circuit board.
Why do silicones excel in Conformal Coating applications?
Silicone elastomers physical properties that make them ideal conformal coatings include:
- easy to use and repair
- excellent electrical properties
- flexibility, mechanical shock and vibration absorption
- resistance to ultra-violet rays, ozone, and weathering
- resistance to humidity, moisture, and water repellency
- excellent thermal stability