Parylene Coating
Chemical Structures
The Dimer and Polymer Structures of Parylene Variants
Parylene N, C, AF4 are commonly used Parylene powders for nano conformal coating on the market and their structures of dimers and film-forming polymers are shown in the table below:
<<Swipe left or right to browse on your phone or tablet>>
Parylene Variants | Dimers | Polymers |
---|---|---|
Parylene N | ![]() | ![]() |
Parylene C | ![]() | ![]() |
Parylene AF4 | ![]() | ![]() |
Coating Properties
Properties of Parylene Coating
The differences in the chemical structure of parylene N, C, AF4 dimer and their film-forming polymers lead to significant differences in some coating properties. The PTEF (Teflon) segment in the chemical structure of the Parylene AF4 film-forming polymer improves the chemical solvent resistance, acid and alkali corrosion resistance, thermal performance, UV resistance and other properties of the Parylene AF4 nano coating. The properties of Parylene N, C and AF4 nano coatings are classified and compared below. The data will vary with the actual application, and the data in the table are for reference only.
Electrical Properties
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
Dielectric Constant (@ 60Hz/1KHz/1MHz) | 2.21/2.20/2.17 | 2.65/2.65/2.65 | 3.15/3.10/2.95 |
Dissipation Factor (@ 60Hz/1KHz/1MHz) | <0.0002/0.002/0.001 | 0.0002/0.0002/0.0006 | 0.020/0.019/0.013 |
Dielectric Strength (V/mil) | 5,400 | 7,000 | 5,600 |
Volume Resistivity (Ohm-cm) | 2.0x10¹⁷ | 1.4x10¹⁷ | 8.8x10¹⁷ |
Surface Resistivity (Ohms) | 5.0x10¹⁵ | 1.0x10¹⁵ | 1.0x10¹⁵ |
Thermal Properties
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
Linear Coefficient of Thermal Expansion (CTE) @ 25°C (ppm) | 36 | 69 | 35 |
Continuous Operating Temp. (°C) | 350 | 60 | 80 |
Short-term Operating Temp. (°C) | 450 | 80 | 100 |
Thermal Conductivity @ 25°C (W/(m.K)) | 0.096 | 0.126 | 0.084 |
Specific Heat @ 20°C (J/(g.K)) | 1.04 | 0.837 | 0.712 |
Thermal Shock | PASS | PASS | PASS |
Flame Resistance | Self extinguishing | Self extinguishing | Self extinguishing |
UV Exposure Time in air (hrs) | Stable up to 2000 | Unstable | Unstable |
Gas Permeability @ 25 °C
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
N₂ gas permeability (cc.mm)/(m².day.atm) | 4.8 | 3.0 | 0.4 |
O₂ gas permeability (cc.mm)/(m².day.atm) | 23.5 | 15.4 | 2.8 |
CO₂ gas permeability (cc.mm)/(m².day.atm) | 95.4 | 84.3 | 3.0 |
H₂ gas permeability (cc.mm)/(m².day.atm) | NA | 212.6 | 43.3 |
Barrier Properties
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
Water Vapor Transmission Rate (g.mm/m²day) | 0.22 | 0.59 | 0.08 |
Water Absorption (% after 24 hrs) | <0.01 | <0.1 | <0.1 |
Chemical Resistance
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
Coated PCB Salt Fog Test for 144 hrs | PASS | - | - |
70% Nitric acid, % Swelling @RT | 0 | 0.2 | 0.2 |
70% Nitric acid, % Swelling @75 °C | 1.2 | Brittle | 1.8 |
95-98% H₂SO₄, % Swelling @RT | 0 | 0.2 | 0.4 |
95-98% H₂SO₄, % Swelling @75 °C | 2.8 | 5.3 | 5.1 |
Mechanical Properties
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
Tensile Module (psi) | 380,000 | 350,000 | 460,000 |
Tensile Strength (psi) | 7,500 | 7,000 | 10,000 |
Yield Strength (psi) | 5,000 | 6,100 | 8,000 |
Rockwell Hardness | R122 | R85 | R80 |
Yield Elongation (%) | 2.0 | 2.5 | 2.9 |
Elongation to Break (%) | Up to 200 | Up to 250 | Up to 200 |
Coefficient of Friction Static/Dynamic | 0.15/0.13 | 0.25/0.25 | 0.29/0.29 |
Other Properties
<<Swipe left or right to browse on your phone or tablet>>
Properties | Parylene AF4 | Parylene N | Parylene C |
---|---|---|---|
Reflection Index (ND23) | 1.56 | 1.66 | 1.64 |
Penetration Ability (aspect ratio) | 50xdiameter | 40xdiameter | 5xdiameter |
Water Contact Angle | 101.83° | 74.84° | 78.61° |
USP Class VI Polymer | Yes | Yes | Yes |