EPOXY POWDER COATINGS FOR CONFORMAL COATING AND CORROSION PROTECTION OF COPPER

Epoxy powder coatings were utilized to form thin, highly resistive, low-defect-density coatings on copper. Substrates having protrusions or sharp edges required greater coating thickness to achieve the same defect density. The following properties of the coatings were studied: adherence, wettability, flow characteristics at cure temperature, stress, resistance of the cured coating to aggressive environments, and the delamination tendency in the presence of an applied cathodic potential. The electrical properties were determined using electrochemical impedance spectroscopy, the application of a constant DC potential, and the application of a cyclic increasing DC potential. The conformal properties of a substrate/coating system can be well characterized by these techniques, and the techniques serve a useful role in predicting corrosion-related failures.