Investigation of screen printed micro-electrodes and paste rheology

Abstract

This study examines the relationship between paste properties and screen-printing phenomena. Since the printing includes multiple processes those are generated almost simultaneously, it is necessary to investigate respective processes. In this report, we have focused transfer printing processes from the screen to a substrate. We have tested model silver pastes with different surface treatment to the silver particles. Several kinds of rheological properties of test pastes were measured and results of model printing experiments and real fine line electrode printings were correlated to the properties. It was found that the shear stress characteristics in the bulk form did not directly relate to printing performance and the other factors, such as oil absorption volume which affected flowability of the paste surface, must be further important. The study also confirmed that the tendency in oil absorption volume agreed with the conventional size electrode printing performance. But, paste residual phenomena was generated in the case of ultrafine line printing with 30 μm width and printing performance was influenced with other factors because of very narrow gap generated with a mesh and open area in the screen.