Improving surface roughness of the 3D printed part using electroless plating

Abstract

The effect of electroless metallic coating on 3D printed acrylonitrile–butadiene–styrene plastic parts surface has been studied. Owing to its excellent toughness, good-dimensional reliability, good-process capability, chemical resistance and cost-effectiveness, acrylonitrile–butadiene–styrene is used for fabrication of parts using a 3D open source printer. These parts are further metallic coated using electroless copper deposition technique. Two different surface preparation processes, namely aluminium paint paste and aluminium epoxy paste have been used for electroless coating. After the surface conditioning of parts using these methods, copper is deposited electrolessly using acidic solution, containing 12.5 wt% copper sulphate with 7.5 wt% of sulphuric acid. Deposition of copper, for two different methods, has been carried out using different temperature conditions and different time of deposition. In the first case, the temperature of the solution is initially kept at 45±2 ℃ and is allowed to come to the room temperature as the deposition is completed. In the second case, the temperature of the solution is maintained at room temperature throughout the process. Further, copper-deposited 3D printed parts were characterized based on their surface roughness measurement, electrical conductivity measurement, scanning electron microscopy, energy dispersive spectroscopy and adhesion evaluation test. It has been found that both the methods used for coating show better electrical performance and more uniform copper deposition. Adhesion between copper layers and 3D printed acrylonitrile–butadiene–styrene substrates is found to have good strength for Al-Epoxy-coated parts.