Why Use Parylene

• Parylene is unique in being created directly on the surface at room temperature.
• There is no liquid phase involved. Coatings are truly conformal, of uniform controllable thickness, and are completely pinhole-free at thicknesses greater than 0.5µ.
• Parylene coating completely penetrates spaces as narrow 0.01mm
• No initiators or catalysts are involved in the polymerization so the coating is very pure and free from trace ionic impurities.
• Room temperature formation means the coatings are effectively stress-free.
• Parylene is chemically and biologically inert and stable and make excellent barrier material.
• Parylene is unaffected by solvents, have low bulk permeability and are hydrophobic. Coatings easily pass a 100hr salt-spray test.
• Parylene has excellent electrical properties: low dielectric constant and loss with good high-frequency properties; good dielectric strength; and high bulk and surface resistance.
• Parylene has good thermal endurance: Parylene C performs in air without significant loss of physical properties for 10 years at 80°C and in the absence of oxygen to temperatures in excess of 200°C.
• Parylene is transparent and can be used to coat optical elements.
• FDA approval of parylene-coated devices is well-documented. The coatings comply with USP Class VI Plastics requirements and are MIL-I-46058C / IPC-CC-830B listed.
• Parylene coatings are completely conformal, have a uniform thickness and are pinhole free. This is achieved by a unique vapor deposition polymerization process in which the coating is formed from a gaseous monomer without and intermediate liquid stage. As a result, component configurations with sharp edges, points, flat surfaces, crevices or exposed internal surfaces are coated uniformly without voids.
• Parylene coating provides an excellent barrier that exhibits a very low permeability to moisture and gases.
• Parylene coating has excellent mechanical properties, including high tensile strength.
• Parylene is stable over a very wide temperature range (-200 'C to +200 'C), allowing the chamber items coated in Parylene to be put in an autoclave.

Parylene Adhesion to Stainless Steel

Any substrate that is vacuum-stable can be coated and the Parylene coating adheres strongly to all materials, even stainless steel, provided the appropriate adhesion-promotion techniques are used.

Parylene coatings perform well as dry lubricants: static and dynamic friction coefficients are equal and comparable to fluoropolymers with the advantage that they also have good wear and abrasion resistance.