Fine Line Double Printing and Advanced Process Control for Cell Manufacturing

In this paper the latest applications of screen printing technology for solar cell metallization are reviewed. The principal achievement is 36 μm Double Printing finger width allowing +0.2% absolute efficiency gain compared to baseline Single Printing process. Dedicated rheology analysis of Ag pastes and measurements of equivalent optical finger width have been performed to have a better understanding of optimal process conditions, together with Stencil Printing experiments, showing the viability of Stencil Printing only for laboratory applications. In the last section, Advanced Printing Control is introduced as a potential enabler of controlled deposit on fingers and busbars, aiming at an increased process window and further cost savings.