Micro-extrusion printhead with offset orifices for generating gridlines on non-square substrates

Abstract

A solar cell extrusion printing system that uses a micro-extrusion printhead to print longer central gridlines and one or more pairs of shorter 'side' gridlines such that end points of the gridline sets form step patterns on an octagonal (pseudo-square) substrate. The printhead includes a set of central nozzles that receive ink from a first valve by way of a first flow channel to print the longer central gridlines, and additional sets of side nozzles that receive ink from additional valves by way of additional flow channels to print the shorter 'side' gridlines. The central nozzles have outlet orifices that offset in the process direction from side outlet orifices of the side nozzles. A start signal is simultaneously sent to the valves such that ink is substantially simultaneously extruded through both the central and side orifices, whereby the extruded ink produces gridline endpoints having the desired step pattern.