Parylene AF4 (CAS No. 3345-29-7)

Parylene finds widespread use in various applications like aerospace, automotive, medical, semiconductor, and electric. It is a polymer that is best-suited for conformal coatings because of its inert nature. Parylene is an excellent barrier coating, and therefore, it has rapidly found use in tiny coating parts, for example, circuit board components.

Parylene AF-4 is the only parylene type that displays a consistent degree of UV-resistance, one wherein performance is maintained relatively long-term. Like the other parylene types, AF-4 also forms an effective, structurally continuous protective film as thin as several hundred angstroms, due to uniqueness of the chemical vapor deposition (CVD) process used to coat substrate surfaces.

Also called aliphatic fluorinate, AF-4 replaces the alpha hydrogen atom of the N dimer with fluorine, and totals 4 atoms. This compositional variation allows AF-4 to generate the lowest parylene coefficient of friction and dielectric constant throughout UV-exposure, and the highest penetrating ability. AF-4 is also useful in high temperature, short-term applications up to 450°C.

Unmatched UV stability

Excellent thermal stability at high service temperature (350)

Unmatched oxidation stability

Completely conformal coating

Superior crevice penetration, pin hole free

Anti-saline damage

Anti-stick ion

Chemical insolubility and solvent resistant

Low water absorption

Hydrophobic properties

Low gas permeability , no out-gassing

Transparent

Light-weight and ultra-thin

Low CTE

Low coefficient of friction

Good dry lubricity

Abrasion resistance

Stabilization of components and structures

Particulate immobilization

Electrical insulation

High dielectric strength

High volume resistivity ,ohm-cm

Low dissipation factor

Low dielectric constant

Mitigation of tin whisker growth

Biocompatibility and bio-stability

USP class VI

Microorganism resistance

Parylen AF4 is extremely useful in high temperature applications and those in which long-term UV stability is required.

Aerospace

Military

Electronic

Medical

Industrial

Semiconductor (3D IC TSV electrical insulation , AMOLED De-bonding layer , Barrier layer )

Bio-MEMS electrode protection film

EWD (Electro Wetting Device) Liquid lens

Parylene AF4 Polymer is superior to most liquid-based coatings like acrylic or silicone. The parylene is an excellent coating for protecting aerospace PCBs and many other electronic components and assemblies. The encapsulation conforms amazingly on all kinds of device surfaces, including edged services, complex creviced services, flat or round surfaces. Another plus point of the polymer is that the coating does not increase the weight of the coated device in anyways.