First discovered in the 1940s, parylene is a polymer created from a chemical compound known as dimer, which is actually a powder. The dimer is then vaporized, made to undergo pyrolysis, transformed into a gaseous state (now a monomer), cooled, and then introduced to a vacuum chamber where it polymerizes and becomes a film. This film is then deposited on virtually any available surface – all at a very low pressure at, or near, room temperature. This entire process is known as CVD, or Chemical Vapor Deposition.
During the deposition process, the vapor produced during this process settles to become a thin protective coating, which is actually parylene. Unlike liquid coatings, parylene completely penetrates all crevices and uniformly coats surfaces, such as sharp points, cavities, edges, corners and even the most minute of pores. Parylene conforms to almost any exposed surface and is free of any small holes or weak areas. This thorough coating provides unsurpassed barrier protection against organic and inorganic compounds.