The reliability of protective PCB assembly coatings, with regard to climate and harmful gas safety, is essentially determined by the uniform application of the coating without interferences or gaps in the protective layer.

In particular, common trouble areas such as solder joint edges and pore channels in coating pooling areas, when lacking a proper coating layer, have detrimental effects on the final board assembly.

The Zestron Coating Layer Test utilizes a black color reaction as a visual indicator of the defects in the protective coating, even in the case of μ-coatings. The test thus adds the standardized methods for coating thickness measurement by enabling rapid detection of closed and dense coatings.

The indicator liquid can also be used to check the readiness for solderability of components prior to soldering. Therefore, the test can also be used during production for cost-effective sampling.