Corrosion Analysis

摘要

SEVERAL BOARD ASSEMBLIES had failed in the field and exhibited areas of corrosion in close proximity to assembled components. The most common source of corrosion on electronic assemblies is residual flux. Fluxes are specific chemistries applied during soldering that improve wetting of the solder to the pad and component when forming the solder joint. They can be highly reactive chemicals that, if left on the assemblies, can lead to corrosion, electrical degradation and decreased reliability. In the presence of moisture and electrical bias, flux residue can enable dendritic growth as a result of electrochemical migration (ECM).