Protective coating layers are applied to electronic assemblies to increase the reliability by keeping them free from climate and harmful gas interference. Edge loss at connection contacts of the coating and pore channels in coat pool areas should be quickly identified and eliminated, as they can lead to failure of the assembly.

With the help of the Coating Layer Test from ZESTRON, non-closed layers are easily identified by a chemical reaction that colors them black. This inexpensive, quick test can be used for random samples during production. In addition to the detection of defects in the protective coating of the assemblies, the coating layer test also functions as a solderability test for components.