Parylene N differs from other Parylene variants primarily in its halogen-free chemistry, lower dielectric constant, and exceptional ability to penetrate complex geometries. Because it contains only carbon and hydrogen, Parylene N offers high chemical purity and excellent electrical performance while being free of halogens, making it particularly valuable in high-frequency electronics, MEMS devices, and applications requiring ultra-thin conformal coatings, that also mitigates the risks of corrosive gas formation when burned, and mitigates the risk of corrosive halogen radical formation when exposed to atomic oxygen in low earth orbit (LEO) and other challenging aerospace environments.
However, compared with Parylene C, D, or F, Parylene N generally provides higher moisture-barrier permeability and lower maximum temperature capability, which means it is not always the best option for harsh environmental protection, where very high temperatures and relative humidity are of the greatest concern Please note though, that when compared most conventional conformal coatings, Parylene N provides excellent moisture barrier performance.
| Parylene Variant | Key Advantage | Main Limitation | Typical Application |
| Parylene N | Lowest dielectric constant, halogen-free chemistry, excellent penetration | Weaker moisture barrier than C |
RF electronics, MEMS, biomedical devices |
| Parylene C | Strong moisture and chemical barrier | Higher dielectric constant |
General electronics protection |
| Parylene D | Higher thermal and barrier performance than C | Less commonly used; high sticking coefficient and deposition rate leads to more challenging (worse) coating uniformity | Industrial and high-reliability electronics |
|
Parylene F (AF-4) |
Very high temperature capability | Higher cost and specialized use | Aerospace and extreme environments |
Parylene N is the base polymer in the Parylene family, consisting of poly-para-xylylene without any halogen substitution. The coating forms via a vapor-phase deposition process, in which a paracyclophane dimer is sublimated, pyrolyzed into a reactive monomer, and polymerized directly on surfaces.
Unlike other variants, Parylene C contains one chlorine atom, Parylene D contains two chlorine atoms, and Parylene F contains four fluorine atoms per repeat unit. Because Parylene N is composed solely of carbon and hydrogen, it offers contains only carbon and hydrogen, it provides exceptional chemical purity and predictable electrical properties.
The key difference between Parylene N and other variants lies in molecular substitution. Parylene N uses an unsubstituted aromatic ring, while other variants introduce halogen atoms to alter performance characteristics.
Halogen substitution changes several properties, including barrier performance, thermal stability, electrical properties, and chemical resistance.
One of the most important advantages of Parylene N is its low dielectric constant.
| Material | Dielectric Constant |
| Parylene N | ~2.65 |
| Parylene C | ~3.15 |
| Parylene F (VT4) | ~3.1 |
Like all Parylene coatings, Parylene N is deposited through chemical vapor deposition (CVD), producing extremely uniform coatings that conform to complex surfaces.
Parylene N’s polymerization behavior allows it to penetrate extremely small features including microvias, fine-pitch electronics, MEMS structures, and narrow gaps. This feature is known by different names across industries, including “crevice penetration,” “penetration depth,” “throwing distance,” “gap fill,” etc.
Because Parylene N contains no chlorine or fluorine atoms, it is considered halogen-free. This characteristic is valuable in applications where chemical purity is critical.
While Parylene N excels in electrical performance, it is generally not the best Parylene variant for moisture protection. Parylene C is widely recognized for its superior moisture barrier properties. In applications where the presence of halogens may be an issue, Parylene N still offers a good moisture barrier, but may require a greater thickness than that of Parylene C to provide a similar level of moisture protection.
Halogen substitution also affects thermal behavior. Parylene N provides moderate thermal stability, while fluorinated Parylene variants offer much higher temperature capability.
Parylene N is typically selected when applications require low dielectric constant, stable electrical performance, halogen-free materials, ultra-conformal coatings, high chemical purity, and high lubricity.
Parylene C is often preferred when moisture protection is critical, chemical barrier performance is needed, or general environmental protection of electronics is required.
COMPARE PARYLENE VARIANTS WITH OUR DATA SHEET
Parylene N offers halogen-free chemistry, excellent dielectric performance, and superior penetration into complex geometries. However, it generally provides lower moisture barrier performance than Parylene C.
Is Parylene N halogen-free? Yes. Parylene N contains only carbon and hydrogen atoms.
Does Parylene N have the lowest dielectric constant? Yes, among commonly used Parylene coatings.
Is Parylene N better than Parylene C? Not necessarily. Parylene N offers better electrical performance while Parylene C offers stronger moisture barrier protection.