Parylene Properties

A Brief Introduction to Parylene

Parylene is the generic name for a unique series of polymers based on paraxylene. Unlike other more conventional types of conformal coatings, Parylene does not have any liquid phase and is applied at ambient temperature through a vacuum vapor deposition process without traditional curing time.

PARYLENE TYPES

The three most common types of Parylene used in industrial applications are Parylene C, Parylene N, and Parylene D.  These types are the obvious choice for 95% of all Parylene application with each type having its own unique electrical and physical properties. Parylene F is used in few select applications where substates are exposed to relatively higher temperatures.  Type F is the costliest Parylene material available in the market and less commonly required.

Parylene C

• Most common Parylene type 
• Useful combination of properties for most types of applications
• Extremely low permeability to moisture, chemicals, and corrosive gasses
• Average crevice penetration activity
• Deposits onto substrates faster than Parylene N

Parylene N 

• Highest dielectric strength
• Dielectric constant does not vary with changes in frequency
• Best selection where greater coating protection is required
• Commonly used in high frequency applications
• Most often used on elastomers/rubbers for lubricity
• Removes tackiness
  

Parylene D 

• Greatest thermal stability compared to C and N
• Maintains physical strength and electrical properties at higher temperatures
• Lowest crevice penetration activity

PARYLENE PROPERTIES

Parylene possesses several valuable properties that set the material apart from other conformal coatings. 

Relative Hardness – Parylene provides superior mechanical protection at thicknesses utilized for conformal coating applications compared to epoxy and polyurethane hardness. Learn more about Relative Hardness.

Thermal Properties – The coefficients of thermal expansion of the Parylene are similar to epoxies and Parylene is capable of withstanding exposure to cryogenic temperatures. Learn more about Thermal Properties. 

Electrical Properties – Parylene displays excellent dielectric strength, is a dielectric constant and has a consistent dissipation factor. Learn more about Electrical Properties. 

Physical & Mechanical Properties – Parylene is unmatched when it comes to tensile strength, yield strength and elongation, coefficient of friction and hardness. Learn more about Physical & Mechanical Properties.

Barrier Properties - Due to the physical properties of Parylene and the method of deposition, the film is pin-hole free and provides an excellent barrier to both liquids and gasses. The gas and moisture vapor permeability characteristics far exceed that of liquid coatings. Learn more about Barrier Properties. 

Optical Properties - Parylene exhibits very little absorption of light and is therefore transparent and colorless.  If a substrate is used outdoors and repeatedly exposed to direct sunlight, it is recommended to apply UV protection on top of Parylene. Learn more about Optical Properties. 

Advanced Coating performs ongoing and thorough testing of the Parylene types and their performance. Detailed documentation is available upon request.