Silver ink experiments for silicon solar cell metallization by flexographic process

The metallization of silicon solar cells becomes more and more critical due to the recent soaring prices of silver. Flexographic printing can be used to deposit the seed layer in a “seed and plate” scheme to replace screen printing, classically employed in production lines but limited by its resolution. To develop the process, several inks prepared from standard screen printing paste were tested. First, different rheological experiments were performed. Then the different inks were printed on silicon solar cells and a correlation was pointed out between rheological properties and printing results. The present work demonstrates that flexography is a potential candidate to deposit silver seed layer with a width as low as 30 μm with a printing speed of 0.5 m/s. Moreover the importance of rheological experiments during a printing process development is underlined.