Electrochemical Corrosion Kinetics across Dissimilar Conductor Interfaces
Electrochemical corrosion kinetics across dissimilar conductor interfaces accelerate through moisture condensation, demanding perimeter sealing and barrier plating.
Parylene-C Coating
Meaning
Vapor deposited polymers provide a thin and conformal protective layer over electronic circuits and components. A parylene-c coating is used in battery management systems to provide a high level of moisture and chemical resistance without adding appreciable weight or volume. This material is unique because it is applied in a vacuum as a gas, allowing it to penetrate every small gap and cover every surface uniformly.
Protective Barrier
Insulation against electrical shorts and environmental corrosion is the primary function of this layer. Because a parylene-c coating is completely pinhole free even at very low thicknesses, it offers superior protection compared to traditional spray on coatings. This makes it ideal for high density circuit boards where the spacing between components is very tight.
Chemical Stability
Resistance to acids and organic solvents ensures that the electronics remain functional even in the event of a cell leak. The inert nature of a parylene-c coating prevents it from reacting with the battery chemistry or the environmental pollutants it might encounter. This stability is maintained over a wide range of temperatures, from extreme cold to the high heat of a fast charge.
Application Benefit
Precise control over the thickness of the film allows for the protection of delicate parts without interfering with their mechanical function. Unlike liquid resins, a parylene-c coating does not pool in corners or pull away from sharp edges during the curing process. This uniformity is a major advantage for ensuring the reliability of the safety critical sensors and controllers inside a battery pack.
The process ensures that even the most complex geometries receive a complete and even layer of insulation, which is important for preventing the formation of conductive bridges in high humidity.