What is the performance of Parylene?
Parylene coatings are superior to all other coating methods in the following properties:
- Continuity of the coating thickness
- Coverage of edges and spikes
- Penetration into extremely thin columns
- Tightness with minimum layer thickness
- Barrier properties against permeation of gases and liquids
- Protection against moisture
- Protection against electrical breakthrough
- Protection against oxidation
- Aging resistance and protection against material aging
In addition to the basic type and halogen-free Parylene N, the types Parylene C, Parylene D, Parylene F-VT4 and Parylene F-AF4 are used commercially. All Parylene types have the properties mentioned before.
But if special requirements are needed, e.g. regarding high-temperature stability, electrical properties or barrier properties, so the Parylene type should be chosen with the most suitable properties.
Parylene are derivatives of benzene. The basic form of Parylene N consists of a benzene molecule. At the benzene ring, at two corners, each hydrogen atom is replaced by a CH2 group. The prefix "para" (abbreviated "p") indicates that these two CH2 groups are attached to the opposite corners of the benzene hexagon.
Parylene N is therefore a pure hydrocarbon.
But one or more hydrogen atoms can be replaced by halogen atoms at the Parylene molecule. Halogens are the chemical elements fluorine, chlorine, bromine and iodine. Thus, a variety of parylene derivatives can be formed theoretically. Only the types parylene N, parylene C, parylene D and parylene F-VT4 are of practical importance. In addition, there is the Parylene F-AF4.