In automotive applications, printed circuit board assemblies are exposed to many aggressive environmental factors, such as moisture, high and low temperatures, mechanical stress, etc., which make the circuit even more sensitive to corrosion of electronic components. For this purpose, a conformal coating is applied to the surface of the printed circuit board assembly, which serves as a primary layer of protection against the aforementioned factors. Before applying the conformal coating, the surface must be cleaned and activated, thereby ensuring optimal wettability and adhesion. There are several surface pre-treatment processes, including the use of open-air plasma.
The aim of this diploma thesis was to review the literature on the use of plasma and based on experiments, optimize the process of surface cleaning and activation with open-air plasma technology. The research also included quantitative measurements of the cleanliness and wettability of the surface, as well as measurements of the adhesion of the conformal coating on the plasma-treated and untreated surface with a "cross-cut" test.
The results indicated that the plasma treated surface is significantly more wettable and the adhesion of the applied coating is superior.
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