Conformal Coating Selection: Weighing the Pros and Cons for Your Application
Parylene Coating Blog by Diamond-MT
Acrylic and urethane conformal coating are widely used conformal coatings. While they share the same methods of applications and ultimate end item uses, there are some differences that should be addressed prior to deciding what conformal coating is the best for your project.
Parylene conformal coating is a very robust coating, but sometimes it is not the right fit for a customer’s application for one reason or another. The entire conformal coating process is based on first identifying the standards to be used and customer’s protection desired. It would therefore only make sense that there are alternatives to parylene for different conformal coating demands.
Silicone Conformal Coating
Tags: conformal coating, silicone conformal coating, tin whisker mitigation, urethane conformal coating, type sr conformal coating, Humiseal 1A33, type ur conformal coating, conformal coating consultation
- HumiSeal 1A33
- HumiSeal 1A20
- Humiseal 1A27
- Humiseal 2A64
- HumiSeal 1A34
- Hysol PC18M
- CONATHANE CE-1155-35
- CONAP CE-1170
- CONATHANE CE-1164
- Techspray Fine-L-Kote
- MG Chemicals 4223
- Electrolube PUC
You should consider using type ur conformal coating whenever your application has any issues with chemical resistivity as type ur coatings are very resistant to chemical solvents. Type ur conformal coating is also smart to include in any tin whisker mitigation strategy, as NASA studies have shown that urethane conformal coatings are one of the few ways to successfully mitigate tin whisker growth. Finally, applications that can see any direct mechanical wear against the coating should consider urethane conformal coatings as well.
Tin whiskers are electrically conductive, crystalline structures of tin that sometimes grow from surfaces where tin (especially electroplated tin) is used as a final finish. They typically grow from lengths of 1-2 millimeters (mm) but have been observed to lengths in excess of 10 mm. They are a serious issue in the electronics world because they have been known to cause short circuits between circuit elements.
Conformal Coatings are used regularly in an attempt to cover technology designs on printed circuit boards (PCBs). Normally, this is done by using a pigmented (coloured) conformal coating which obscures the components below the conformal coating material.
Urethane conformal coating is becoming an increasingly popular conformal coating choice. However, it is not suitable for all applications. Instances where the product is going into a high vibration environment or has a high heat requirement would not ideal candidates for urethane conformal coatings.
In applications that have an exposure to solvents, acrylic conformal coating is not the best choice. Acrylic conformal coating can be removed with a weaker solvent such as isopropyl alcohol or xylene. Whenever it faces even stronger solvents, it will not offer the protection that is needed, especially if your product is a mission critical device. Other coatings, such as urethane or parylene conformal coating have a far better resistance to solvents than acrylics.
Tags: acrylic conformal coating, parylene conformal coating, conformal coating, silicone conformal coating, conformal coatings, HumiSeal 1B31, urethane conformal coating, HumiSeal, epoxy conformal coating