Polymer Coating
Vapor-deposited polymer films provide uniform environmental protection for sensitive electronic assemblies. The chlorinated dimer parylene c is widely used to create high-purity conformal coatings on printed circuit boards and sensor elements.
Deposition Process
Chemical vapor deposition under vacuum allows the coating to grow uniformly on all exposed surfaces. During this process, raw parylene c dimer is vaporized, pyrolyzed into a monomer gas, and then deposited as a polymer film at room temperature. This gas-phase deposition allows the material to penetrate beneath tightly spaced components and into narrow crevices.
It results in a pinhole-free layer that does not suffer from run-off or pooling.
Barrier Efficiency
Inhibiting the penetration of moisture and ionic contaminants protects copper traces from dendritic growth and corrosion. The high barrier efficiency of parylene c makes it suitable for medical implants, aerospace sensors, and automotive modules exposed to condensation. It remains stable under a wide range of temperatures and chemical exposures.
This stability ensures long-term operational reliability in hostile environments.
Insulation Test
Measuring the insulation resistance of the coated assembly under high-humidity conditions confirms the quality of the barrier. Production lines test parylene c coatings by applying a high voltage and monitoring the leakage current between adjacent traces. Failure to meet the minimum resistance limit indicates incomplete deposition or contamination on the board surface before coating.
This test constitutes an important gate in medical device manufacturing.
