Novel formaldehyde-free electroless copper for plating on next-generation substrates

Abstract

This work describes a new type of formaldehyde-free electroless copper electrolyte that can be used for a broad set of applications and materials, especially for the processing of next-generation substrates. The plating solution was successfully applied in both, a laboratory and production-scale environment. The results have been evaluated in detail and were benchmarked against a formaldehyde-based reference. A characterization of the obtained metal films was carried out by different analytical techniques, including microscopy, X-ray fluorescence (XRF), scanning electron microscopy (SEM), adhesion tests and non-blister verification. Additionally, studies concerning chemical bath stability, throwing power and electrical reliability have been made. Based on the obtained data we believe that the current achievements represent a suitable technology to replace formaldehyde in existing printed circuit board (PCB) production without loss of process performance and thus provide a sustainable "green" alternative to the industry.