Patent ID: 8226391

Claim:
An extrusion system for extruding a bead of extrusion material onto an upper surface of a target substrate, the extrusion system comprising: a printhead assembly including: a bottom plate including a first front edge and a first surface located adjacent to the first front edge; and a nozzle outlet structure including a second front edge and defining an elongated groove extending in a predetermined flow direction from a closed end to an open end defined through said second front edge, said elongated groove including an open edge having a first width and a closed edge having a second width that is smaller than the first width, wherein the bottom plate is mounted on the nozzle outlet structure such that the first surface is mounted over the open edge of the elongated groove to form an extrusion nozzle having a tapered cross-section defined by said elongated groove, wherein the elongated groove defines an outlet orifice defined by the open end of the elongated groove; and means for forcing extrusion material through the extrusion nozzle such that said extrusion material substantially fills the extrusion nozzle as said extrusion material flows in the flow direction and out of said outlet orifice to form said bead, whereby said bead has a cross-sectional shape that is essentially identical to the tapered cross-section of the extrusion nozzle, wherein the extrusion nozzle includes a central channel and two side channels that converge with the central channel at a merge point located adjacent to the opening, and wherein the extruded bead includes a functional material transferred through the central nozzle channel and a sacrificial material transferred through the two side channels such that the functional material forms a high-aspect ratio gridline structure on the substrate that is supported between two portions of said sacrificial material, and wherein the central channel and two side channels comprise troughs defined in said plate, and wherein said elongated groove is defined in said trough forming said central channel.