Conformal coatings provide a long-term, stable and reliable encapsulation method for the electronic components from the environmental effects. Different industries and service conditions calls for different protective coatings. In some cases, changes in the requirements or mistakes would call for action to remove the coating. While some coating materials are easily removed, some are virtually impossible to remove without damaging the products (eg. epoxy) . The coating removal process has been standardized by the standard IPC-7711C/7721C titled Rework, Modification and Repair of Electronic Assemblies . According to the IPC-7711C/7721C coating removal starts by the identification of conformal coating (Chart. 1) type and followed by the selection of the method to be used depending on the substrate and components. If prepared onsite the coating material is generally known, but if the coating was done elsewhere the following chart can be used to identify the type of conformal coating.Read More
Parylene Coating Blog by Diamond-MT
Parylene’s CVD method of application generates exceptionally lightweight yet durable conformal coatings, with superior barrier properties. Compared to liquid processes, the effects of gravity and surface tension are negligible, so there is no bridging, thin-out, pinholes, puddling, run-off or sagging.Read More
Despite parylene’s numerous benefits as a conformal coating, it has several disadvantages that should be recognized before it is used. Failure mechanisms that can emerge from parylene coatings have limited its wider scale application in comparison to liquid conformal films such as acrylic, epoxy, silicon, and urethane. In many situations, wet coatings can provide better performance and lower cost (or both) for many applications.Read More
Despite conformal coatings’ ability to dependably protect substrate surfaces of printed circuit boards (PCBs) and related electrical components, problems can sometimes occur which compel their removal. Chemical removal, which does the least damage to PCBs, is fine for wet coating substances like acrylic, epoxy, silicon and urethane. Chemical removal methods are far less successful for parylene, despite the use of a chemical vapor deposition (CVD) process for its film application.Read More
Removal of Conformal CoatingsRead More
Parylene's benefits as a conformal coating are well known. It resists heat, cold, moisture, and pressure; salt spray, electricity, and solvents can't permeate it. And while these attributes of parylene contribute to the conformal coating's appeal, they also present distinct challenges, particularly in regards to parylene removal, rework, and repair.