Deposition Process

Understanding the Technology

Parylene polymers are deposited from the vapor phase by a process in which all sides of an object to be encapsulated are uniformly impinged by the gaseous monomer at pressures at around 10 to 30 mTorr (Millitorr). 

The ultra-thin Parylene film is formed by the pyrolysis of a di-p-xylene (dimer) in a vacuum environment which is then deposited on a cooler (i.e. room temperature) substrate inside the deposition chamber while under continuous vacuum.

The three-phase vapor deposition of Parylene polymer allows it to be formed as a structurally continuous film which is truly conformal to the design and structure of the substrate upon which it is being deposited.

Parylene can be effectively deposited with excellent accuracy in thickness over a range from 0.2 µm (microns) to well over 8 mils.

The Parylene Vacuum Deposition Process

Phase 1 - Vaporization

The Dimer is added to the Vaporizer and is heated to 75-250 degrees Celsius depending on application and Parylene type.  The dimer turns from a powder into a vapor.

Phase 2 – Pyrolysis

The Dimer is heated up further in the furnace at 600 – 700 degrees Celsius and becomes a monomer.

Phase 3 – Deposition

Dimer turns into a polymer that adheres evenly as transparent Parylene film to the components inside the coating chamber at ambient temperature.

The Cold Trap collects and condenses excess monomer from vacuum chamber and the Vacuum Pump maintains constant vacuum throughout the process.

The Parylene coating process does not include any liquid phase and there is no traditional curing time involved.

The Art of Deposition

Our parylene coating experts know that, while "the science side" of the deposition process is important, there is a necessary artistic touch that's just as crucial. Here's a quick look!

• Substrates. Each unique substrate material to which parylene can be applied--including metal, plastic, paper, and more--has its own specific needs. Although parylene can cater to all of these needs, it often requires a bit of help in the form of A-174 silane applied before coating. Experts have perfected the art of deposition to the point where any substrate material can be coated with all the reliability and precision expected of parylene coatings.
• Cleanliness. The artistic side of parylene's deposition process demands a high level of cleanliness. Anything that is not part of the substrate--from human oils to dust particles--can interrupt the deposition and impact the performance and safety of the parylene. As a result, there are countless standards in place to ensure purity.
• Preparation. Parylene is a strong and reliable coating, but it can be a bit too strong when it's applied to anything but the substrate material--which is why experts know that the art of preparation is crucial. The inside of the temperature-controlled chamber must be carefully prepared before deposition to protect from an accidental application.

Partner with Advanced Coating

Advanced Coating has decades of Parylene coating experience and can design an ultra-thin protective coating that meets your unique specifications.  Let us guide you through the process to ensure your 100% satisfaction.