In many cases there are applications that require protection against the creation of corrosion/ penetration of various liquids and/or gases.
The outstanding advantage of the parylene coating is its excellent protection against the penetration of liquids and moisture. In fact, no acid/ gas/ base can harm the coating or, alternatively, remove the coating.
The molecular structure of parylene C as observed with x-rays is tricyclic. However, when a longitudinal section is made of parylene, it can be seen that parylene has a lamellar structure resembling dense fish scales that effectively prevent the penetration of liquids, gases or acids.
Impermeability data for parylene regarding various gases and water, compared to other conformal coatings.
The testing of parylene C was done in accordance with ASTM F 1249 (37°C, 90% RH).
The testing of parylene N, D, was done in accordance with ASTM F 1249 (37°C, 90% RH) (ASTM E 96°C).