Project "Innomet" - Evaluation of Innovative Glass-Based Printing Forms for Solar Cell Metallization

Within this work, we discuss the evaluation of innovative glass-based stencils starting with in-depth computational fluid dynamics (CFD) simulation of different channel geometries using COMSOL Multiphysics©. Based on these simulations, a special hour-glass shaped channel geometry has been identified which theoretically enabled the direct printing of contacts with a triangular cross-section using stencil printing. With the expertise of the involved partners LPKF Laser & Electronics AG and Christian Koenen GmbH, several sets of LIDE-structured glass foil stencils have been fabricated and tested on a semi-automatic screen printer at Fraunhofer ISE. Within these tests, the prediction of stencil-printed triangular contacts could be impressively verified on Cz-Si PERC solar cells. Due to the optimal reflection properties of such a contact shape, this could enable effectively "transparent contacts" in the future and thus represents a long-lasting dream of all solar cell metallizing specialists. Furthermore, glass foil nozzle plates were manufactured for the parallel dispensing technique by LPKF Laser & Electronics AG to demonstrate the proof of concept for an alternative, cost-effective material including production costs for nozzle plates compared to the standard material. LIDE-structured glass foils showed promising results in the multi-nozzle dispensing process to be used in the future within further optimization in the manufacturing process.