Mechanical Sensitivity analysis of a sub cell using wire interconnection

Abstract

As explained in the introduction the reliability and durability of PV modules is becoming increasingly important to further reduce the overall cost of PV. A thorough investigation and understanding of the thermo-mechanical phenomena which influence the reliability will provide new insights to further optimize the lifetime of imec’s cell and module technologies. To reach this goal we aim to develop an understanding of failure mechanisms through implementation and verification of abottom-up physics based model utilizing the finite element method. We will study the impact of various material and technology parameters and their respective geometrical differences as well as appropriate approximation, homogenization and multiscale modelling techniques. A separate simulation model will be developed for each of the reliability levels (solder joint- cell- mini- and full-area module) which ultimately can be coupled and thereby predicting the overall mechanical reliability of PV modules for a defined module or cell technology. The simulation models will be verified both by dedicated materials and mechanical tests as well as utilizing industry relevant tests such as thermal cycling and mechanical stress testing. To achieve these goals, the first element to develop within this simulation tool is the cell and its interconnection technology modelling. In 2017 H1 a mechanical simulation model of a sub cell will be developped to industry standard cell with two different kinds of metallization (screen-printed and plated) and verified by experimental measurements using 4-point bending. We will also perform a sensitivity analysis to prepare further explorations.