For the generation of electricity by solar energy it is necessary to contact the silicon wafers by copper strips. These are coated with a solder that melts while the wire is attached on the wafer and thus creates a cohesive connection. Conventionally, SnPb solders are used for this application. Due to the EU Directive 2002/95/EC on the Restriction of Hazardous Substances in electrical and electronic equipment (RoHS), the wire manufacturer Gebauer and Griller Metal Works Ltd. Have to use substitutions of these materials. For producing a marketable lead-free variante in a short time, some alloys based on the ternary SnBiAg systeme were tested. Furthermore different investigations characterised these alloys for the copper coating process and for the application at the photovoltaik module production. Measures against the copper solubility in the melt and the yellowing effect of the tin coated surface were also examined carefully.