GAT offers different variants of high quality parylene dimer including fluorinated parylene VT4(F) and AF4 for sale.
As a coating, parylene C is favored over all other types by a significant margin and is used in virtually all industry segments. Parylene C has a higher temperature resistance (80°C, in air, long term) as compared to parylene N, as well as a higher deposition rate and improved barrier properties. The gap-fill (crevice penetration) properties are not as good as parylene N. See Parylene Properties
Parylene N, although less frequently employed as barrier chemistry than parylene C, has certain properties that favor its use in several applications, particularly as a coating for select medical products and elastomers. Compared to parylene C, parylene N has superior conformality and crevice penetration properties. In addition, parylene N has a high dielectric strength and a dielectric constant value that is relatively independent of frequency, a property useful for RF applications. See Parylene Properties.
Parylene D, or poly-dichloro-p-xylylene, has two Cl atoms on the benzene ring, giving the polymer a higher thermal stability than parylene C. Parylene D films have excellent chemical resistance and barrier properties. See Parylene Properties.
Parylene VT-4, sometimes referred to Parylene-F, is the aromatically fluorinated version of parylene film. This variant of the parylene family also has a relatively high thermal stability and a low dielectric constant. The UV and oxidative stability of this variant is not as good as the parylene AF4 film. However, the relatively lower cost of the dimer material, as compared to the AF4 variant, makes this an attractive choice for many applications. See Parylene Properties.
The aliphatic fluorinated versions of parylene films have the highest thermal stability (>300 °C) of all the parylene variants. In addition to the thermal stability, parylene AF4 is most resistant to UV damage and is frequently used in outdoor applications. Low coefficient of friction and low dielectric constant value are attractive properties for several applications. One of the main disadvantages of the fluorinated parylene AF4 films is the high cost of the raw material.