Quasi-simultaneous laser soldering for the interconnection of back-contact solar cells with composite foils

In this contribution we evaluate laser scanning approaches for the interconnection of the 31 electrical contacts of a MWT back-contact solar cell. The selective energy deposition with a laser system allows the minimization of thermomechanical stress in the wafer, but requires adapted scanning strategies to prevent damages in the solar cell top layer. The laser scanning process of the MWT solar cell is conducted in combination with a composite foil as an interconnector and a pre-dispensed solder paste. This approach is evaluated regarding the joining quality of the interconnection as a function of the scanning strategy.