Packaging. Not the most complex subject when choosing a conformal coating, but treat the decision too lightly at your peril. There are a surprising number of options available, each suitable to very specific needs and conditions. In this brief presentation we will discuss, from smallest to largest, the various packaging choices available to you, along with the advantages and disadvantages of each.
Take a quick look at the photograph on your right. If you are in the business of PCB manufacturing with conformal coatings, does it frighten or concern you at all? Does the magnified coating appear to truly “conform” to the surfaces evenly? And if not, what effect, if any, might this have on the protection of your PCBs?
First of all, don’t panic. What you see in the photograph is not unusual and is not necessarily a problem. It is important, however, that if you are in the business of applying conformal coatings, you should have a clear understanding of some of the unique challenges they present.
How do you select and test a conformal coating that is right for your specific application? Or maybe you would like to create your own test specification due to any special characteristics of your device’s operating environment? Or depending on your geographical location, you may also be required to use a different testing specification that is dictated by local authorities.
A widely used method to create an internal specification, is to simply select a conformal coating material that meets an existing specification standard. Such standard could be MIL-I-46058C or IEC-60664. However, you must be careful to ensure that the existing standard that you choose, does indeed meet 100% of your requirements. In such cases, you may have to specify test methods from other existing standards.