What is a Good Thickness for Acrylic Conformal Coating?

Acrylic conformal coatings (type AR), such as MG Chemicals 419C and HumiSeal^® 1B31, are a very popular conformal coating choice. They are used primarily for moisture protection on printed circuit boards. Often, they are utilized because of their easy-to-use nature. As a result of this, acrylic conformal coating is frequently applied as a DIY project. This frequently results in an issue with improper thickness of coating, resulting in lackluster protection.

So what is a good thickness for acrylics? According the IPC-610, type AR conformal coatings should be between .002” and .005”. The MIL-I-46058C calls for .002” +/- .001”. The optimal thickness of acrylic coating is about .002” to .003”. Meeting this thickness will ensure that the coating application is within spec for two of the major specifications. If thicknesses are not met, it could lead to the failure of the coating and ultimately the printed circuit board it is trying to protect. Specifically for acrylics, the thickness helps prevent moisture ingress on the PCB.

While relatively easy to use, some customers don’t want to set up a conformal coating line or can run into issues when high volume throughput is required. When this is the case, a trusted coating professional can ensure your parts receive the protection they require. Specialty Coating Systems has been partnering with our customers for over 50 years, and our team of engineers and specialists is ready to meet your coating specifications. Contact SCS to learn more.