Conformal coatings like parylene are relied on everywhere, from aerospace to the doctor's office--so it's important that these coatings are trustworthy. One problem that can arise is called "cracking," and it can be a big issue if not taken care of properly. Let our conformal coating experts explain.
Conformal Cracking Issues and Causes
Conformal coating usually covers a substrate surface in a smooth, uniform layer. When cracking occurs, that layer fractures, creating an uneven surface that looks somewhat like a snake shedding its skin. This can be a big problem since every crack is an opportunity for contaminants and moisture to get to the coated surface.
Cracking is often due to temperature problems during the curing or drying process, or, in the case of parylene, when the wrong type or thickness of the coating is used for the wrong job.
Since cracking can lead to system failure or interruption, it's important to apply all preventative measures necessary--and, if cracking does occur, then it's crucial to take care of it quickly.
3 Important Facts About Parylene Cracking
Why is parylene cracking different than cracking in other coatings? What are the most important details? Our conformal coating experts are here to explain.
Application. By nature, parylene is applied differently than other coatings. It is not applied in a liquid form--but varying temperatures during the application process can still cause cracking, so it's important to take extra care.
Thickness. Since parylene's thickness can be so closely monitored, it never hurts to make the coating a little thinner to avoid the possibility of cracking. Parylene remains flexible and reliable at all thicknesses.
Temperature. Temperature has a lot to do with the success of any conformal coating. It's not just varying temperatures, either; if the wrong temperature is used at the wrong time, or a period of extreme heat is followed by extreme cold, then cracking becomes more likely.