Towards a better understanding of the thermo-mechanical behavior of H-pattern cells during metallization

In this paper, we present a fully adaptable three-dimensional finite element (FE) model of a solar cell with silver H-pattern on the front side and a full aluminum rear side. The model is used to simulate the metallization process followed by a four-point bend test. The model was verified by measuring bowing after metallization and force-displacement curves during four-point bending. The four-point bending model allows the ultimate breaking stress for different cell thicknesses to be determined. In combination with the model for the residual stresses generated during the metallization process, the limits of this process with respect to cell thickness can be predicted. Furthermore the robustness and limits of the model are tested using Monto Carlo analysis giving insight into the variables determining stress and bowing.