A natural process, corrosion enacts chemical/electrochemical reactions that degrade and gradually destroy materials or components within a functional environment. The outcome can be dangerous and costly to repair.Read More
Parylene Coating Blog by Diamond-MT
Parylene (XY) polymers provide robust, dielectric, micron-thin conformal coatings for a considerable range of electronic devices, most prominently printed circuit boards (PCBs). XY’s unique chemical vapor deposition (CVD) application method synthesizes in-process, depositing gaseous parylene deep into a substrate’s surface. CVD occurs on a molecule-by-molecule basis, conforming to all underlying contours, regardless of shape or position, to the nanometer, if necessary. Pre-synthesized liquid coatings lack many of parylene’s performance properties, having far less ability to successfully and conformally penetrate crevices in the substrateRead More
Used as moisture and dielectric barriers, polymer parylene (p-xylylene/XY) coatings are conformal and pinhole free. Applied by a unique chemical vapor deposition (CVD) method, parylene penetrates beneath substrate facades, simultaneously attaching above surfaces at the molecular level. CVD generated films cover crevices, exposed internal regions, points and sharp edges uniformly, without gaps or breaches. Compared to liquid coating materials – acrylic, epoxy, silicone and urethane -- XY film layers are micron-thin, enhancing their utility for microelectricalmechanical systems (MEMS) and nano technology (NT).Read More
For conformal coatings, elongation is a measure of material ductility -- a specific coating's ability to undergo significant plastic deformation before rupture. A coating’s yield elongation is the maximum stress the material will sustain before fracture. Thus, computed parylene (XY) elongation measurements represent the total quantity of strain the conformal film can withstand before failure. While elongation is equal to a material’s operating failure strain, it has no exclusive units of measurements. Typically,Read More
Parylene (XY) conformal coatings are applied to substrate materials through a specialized chemical vapor deposition (CVD) process that completely eliminates the liquid phase of wet coatings. No initiators or catalysts are involved in CVD polymerization, which synthesizes truly conformal protective film in-process. This is in stark contrast to wet coating materials such as acrylic, epoxy, silicone and urethane, which are synthesized prior to application via, brush, dip or spray methods. Wet during application, liquid-coated substrates requiring further drying and curing.Read More
Parylene: Properties and ProcessesRead More
Parylene conformal coating (XY) provides insulative protection for complex electronic circuit assemblies expected to function through rigorous operating conditions -- potential chemical, electrical, moisture and vapor incursion during performance. Applied through chemical vapor deposition (CVD), parylene penetrates deep within substrate surfaces, generating a level of assembly security surpassing that offered by liquid coatings such as acrylic, epoxy, silicone and urethane. Yet, although XY is applied in a vacuum, it’s capacity to provide these extraordinary qualities does not exist in one. Parylene’s durable protective value depends on film adhesion, a quality subject to persistent, thorough inspection throughout the production process.Read More
Parylene Chemistry and Production RequirementsRead More
It is imperative to obtain proper adhesion of the coating to the substrate in order to truly reap the benefits of parylene conformal coating. Poor parylene adhesion, after all, can negate some of parylene's most-prized properties, including corrosion resistance, chemical resistance, moisture resistance, and dielectric strength. So, it's in an engineer's best interest to understand the importance of parylene adhesion and how to obtain it.
Parylene and acrylic resins are both conformal coatings. Most of the similarities stop there. Because their properties vary so much, they have their own unique uses and capabilities.