Parylene coating is a common high-performance thin film coating material. It is widely used in electronics, medical, aerospace and other fields for its excellent electrical insulation, chemical corrosion resistance and excellent physical protection properties. One of the core features of Parylene coating is its film-forming process: it converts monomers into thin film coatings through chemical vapor deposition (CVD) technology. In the preparation process of Parylene coating, the most important component is Parylene monomer.
This article will introduce the main monomers of Parylene coating and explore their respective characteristics and applications.

1. Parylene N
Parylene N is one of the most basic and simplest Parylene monomers. Its chemical structure contains only carbon and hydrogen atoms and has low polarity. Its film-forming process is relatively simple, and the resulting coating is transparent and uniform, with excellent electrical insulation and temperature resistance.

Features:
Electrical insulation: Parylene N exhibits excellent electrical insulation after film formation and is suitable for high-frequency electronic devices.
Chemical stability: It can resist the erosion of most chemical substances, such as acids, alkalis and solvents.
High temperature resistance: Parylene N can withstand higher temperatures and is suitable for some high temperature working environments.
Application:
Parylene N coatings are widely used in electronic components, sensors, and other equipment that require electrical isolation and protection. Its transparency and uniformity make it particularly important in precision electronic products.

2. Parylene C
Parylene C is a chlorinated parylene monomer with chlorine in its chemical structure. Compared with Parylene N, Parylene C coatings have stronger chemical stability and better barrier properties, especially in terms of water vapor and other gas barrier properties.

Features:
Enhanced chemical stability: Parylene C has stronger corrosion resistance to most chemicals, including water, acids, and alkalis.
Excellent gas barrier properties: Parylene C exhibits higher performance in many applications that require gas and moisture isolation.
Electrical insulation: Maintains the consistent electrical insulation advantages of the Parylene family.
Applications:
Parylene C is one of the most common parylene coating materials and is widely used in electronic devices, circuit board protection, sensors, battery protection and other applications that require long-term stability. It has a wide range of applications in medical devices, automotive electronics, communication equipment and other fields.

3. Parylene F
Parylene F is a newer parylene monomer and an improved material that is optimized for its higher thermal stability and stronger mechanical properties. Compared with Parylene N and Parylene C, Parylene F has better high temperature resistance and maintains its mechanical stability in environments with drastic temperature changes.

Features:
High temperature stability: Parylene F can withstand temperatures up to around 200°C for a long time, making it an ideal choice for high temperature environments.
Chemical resistance: Parylene F has good UV resistance to most chemicals.
Good mechanical strength: Parylene F has higher rigidity and toughness, suitable for applications that require wear-resistant and high-strength coatings.
Application:
Parylene F is mainly used in high-temperature, high-strength applications, such as aerospace devices, high-temperature electronic component protection, and high-temperature protective coatings for industrial equipment

4. Parylene AF4
Parylene AF4 is a parylene coating monomer designed for high-temperature environments, with higher thermal stability and chemical resistance than Parylene N, C or F. It is often used in extreme environments, such as aerospace, military equipment, and certain special industrial applications.

Features:
Ultra-high temperature performance: Parylene AF4 coatings can maintain stability at temperatures of 350°C or higher, suitable for high-temperature working conditions.
Chemical stability: Able to withstand more severe chemical environments, suitable for electronic equipment under extreme conditions.
Application:
Parylene AF4 is mainly used in extreme environments, such as aerospace, military electronic equipment, and electronic component protection in nuclear power plants.

Summary
Parylene coating monomers come in many different types, including Parylene N, Parylene C, Parylene D, Parylene F, and Parylene AF4. These monomers, through different chemical modifications and structural changes, give the coating different physical and chemical properties, such as excellent electrical insulation, chemical corrosion resistance, high temperature resistance and mechanical strength. Parylene coatings are widely used in high-demand fields such as electronics, electrical, medical, and aviation, providing ideal protection and isolation functions. With the continuous advancement of technology, the application areas and functions of parylene coatings will continue to expand, providing advanced solutions for more industries.