Non-contact printing: Conductive track geometry affected by ink rheology and composition

For printing the front side metallization of solar cells using the non-contact aerosol printer different silver inks with different rheological properties and silver components were tested. Both atomization methods of the aerosol printer are introduced and the optimized printing parameters are discussed. With the most suitable inks and printing parameters it was possible to achieve high aspect ratios within 2:1 up to 4:1 with small lateral resolutions. A particle-free ink and several particle-containing inks for example diluted screen printing pastes were tested as aerosol ink to evaluate the most feasible ink. According to these results it was possible to assess the most important properties for aerosol inks, which are necessary to obtain a good printability and well defined printed structures. High aspect ratios (AR) of 2:1 were achieved by aerosol printing with the pneumatic atomizer for the front side metallization grid of solar cells and efficiencies of 14-17 % were achieved.