Reduction of copper oxides via an atmospheric pressure plasma torch

Abstract

Summary form only given. An atmospheric pressure Radio Frequency (RF) plasma torch has been used in the reduction of surface oxides on bulk copper. A chemically active reducing environment was generated using a hydrogenic plasma. The reduction of copper oxide was investigated over a range of plasma powers and exposure times. Reduced samples were chemically analyzed using X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM). The XPS spectra showed a shift in both the Cu 2p and O Is peaks. These shifts indicate a reduction from copper oxide to metallic copper. Plasma characteristics were analyzed with Optical Emission Spectroscopy (OES) to determine atomic and molecular species present in the plasma. Additional trends on the reduction process from the varying plasma parameters will be discussed. This process gives an alternative contactless and dry method for the removal of copper oxides. It avoids the use of abrasives and harsh acids or chemicals making it suitable for surface treatment in electronics, connections, and welding applications.