These same pastes were also tested for wettability to a CuNiZn substrate. This metallization is a surface commonly found on RF shields and is difficult to wet. Solder non-wetting and dewetting is seen on the comparison pastes even with the shorter linear profile. GC 10 has a shiny solder surface and has fully wetted the substrate metallization. With the longer soak profile D, heavy black oxide along with non-wetting and dewetting are seen on the comparison pastes. The GC 10 wetted well and resulted in a shiny solder surface.