Aluminium Foil and Cold Spray Copper Technology as Cost Reduction Process Step in Back-contact Module Design

MWT cell and module technology has been shown to result in modules with up to 5% higher power output than H-pattern modules [1]. Back-contact modules allow automated processing and are suitable for use with thin and fragile cells. In this study, the use of a low cost conductive back-sheet with aluminium as the current carrier, in combination with locally applied copper (5 to 30 μm) using the cold spray method is benchmarked against a standard PVF-PET-copper foil (TPC3480 from Isovoltaic AG) in 2 x 2 cell modules. Cell to module losses and reliability during climate chamber tests according to two times IEC61215 ed. 2, are comparable to module made with the standard foil. Optimizing the cold spray process can result in a cost reduction of more than a factor 10 of the current carrying component, when compared to a full copper conductive back–sheet foil.