Nordson MARCH, a Nordson® company, recently announced that recent studies have shown that plasma treatment of printed circuit boards (PCBs) prior to conformal coating improves the adhesion of the coatings. It has been found that it is often difficult to apply adequate coating to some of the materials that meet strict environmental requirements, such as the Restriction of Hazardous Substances directive (RoHS). Plasma treatment reportedly enhanced surface wettability, improving adhesion of the conformal coating to high-performance solder mask materials and other difficult-to-adhere-to substrates. In addition, the flow characteristics of the conformal coating material improved when the PCB was treated with plasma.
Additional challenges for conformal coating adhesion are contaminants such as mold release compounds and residual flux. Plasma treatment can be an effective way to clean the boards in these cases, and plasma removes the contaminants without damaging the substrate.
For more information, visit www.nordson.com.