CF4 fluorination onto Cu surface using atmospheric pressure non-equilibrium plasma for flux-less soldering with lead free solder

► Atmospheric pressure non-equilibrium plasma is a good tool for improving material surface properties. ► We applied the plasma treatment with CF4-O2 mixed gasses onto Cu surface to gain wettability of fluxless-soldering with lead-free solder. ► The Cu surface was fluorinated by the plasma treatment; and the contact angle of solder on the surface was minimized at the flow ratio of CF4/O2 was 1/9. ► We showed here surface fluorination by this treatment improves the wettability of flux-less solder.