Parylene coating

OBANG TECHNOLOGY CO., LTD.

What is Parylene coating?


The concept of Parylene coating

Parylene coating is a technology that vaporizes powdery raw materials in a vacuum to form a polymer film layer, and is a coating technology that uses CVD (Chemical-Vapor Depositon).

In the Parylene coating process, the powdered dimer is evaporated by heat, and the evaporated dimer is converted to a monomer through a thermal decomposition unit, cooled before the monomer diffuses into the vacuum chamber, and the cooled monomer is polymerized in the vacuum chamber. A film-type coating film is formed on the object surface.

Since the polymerization reaction of the Parylene coating occurs at a very low pressure and a normal temperature of 30°C or less, it does not generate thermal stress on the surface of the object, and pinholes and pores do not occur because the coating film is formed by a gas-type treatment process.

Unlike the wet coating, the Parylene coating is capable of forming a uniform coating film regardless of the shape even in a product having a complicated shape such as a fine gap, a sharp point, an edge, and a fine hole. Therefore, it is possible to obtain a very useful protective film for products composed of organic and inorganic compounds and organic/inorganic composites.

Parylene coating properties

Immersion or spray

Immersion or spray

  • coating film is non-uniform
    (the coating film is thin at the edges and ends)
  • Pinhole
  • Heat deformation
  • Mechanical deformation
Parylene coating

Parylene coating

  • Uniform coating
    (uniform at both edges and ends)
  • No pinhole
  • No heat deformation
  • No mechanical deformation
  1. 1
    Excellent gas barrier (to H2O, O2, etc)
  2. 2
    Excellent corrosion resistance
  3. 3
    Strong resistance to most chemicals (acids, alkalis and solvents)
  4. 4
    High insulation, low dielectric constant and low dielectric constant
  5. 5
    Excellent flexibility and mechanical properties at very low temperatures
  6. 6
    Excellent radiation resistance in an oxygen-free environment
  7. 7
    Almost no out-gassing
  8. 8
    Standards such as Mil-I-46058C, IPC-CC-830B, UL94 V-0, FDA Drug and Device Master Files, USP Class VI biocompatibility, and ISO 10993 for medical devices

Configuration of Parylene coating device

Configuration of Parylene coating device
  1. 1
    Vaporizer : Apply heat between 80℃~175℃ to make the Parylene dimer evaporate.
  2. 2
    Pyrolyzer : Converts gaseous Parylene dimer into monomer by applying high heat between 650℃ and 690℃.
  3. 3
    Deposition Chamber : Inside the chamber at room temperature, Parylene is polymerized to coat the surface of the object.
  4. 4
    Chiller Trap : It serves to condense the by-products of Parylene generated during the coating process into the cryogenic protection pipe (-70°C to -100°C) so that they do not flow into the Vacuum Pump.
  5. 5
    Vacuum Pump : Maintaining the vacuum of the Vacuum Chamber and all connected parts