Rectangular Backup Hole for Drop-On-Demand Nozzle
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
A low-cost substrate design is described that provides a means for manufacturing closely-packed nozzle arrays for drop-on-demand (DOD) ink jet printers. Nozzle assemblies used in DOD ink jet printheads are formed by an array of nozzles bonded to a rigid substrate having a corresponding array of nozzle backup holes and often utilize etched silicon nozzles bonded to a ceramic substrate. Alignment of the nozzle array with the ceramic substrate is difficult because of the close tolerances involved. Each pyramid-shaped silicon nozzle, typically 14.2 mils square at the nozzle entrance and 2.0 mils square at the nozzle exit, must be centered in the corresponding backup hole. Space must be provided for a fillet formed by an adhesive bond and for differences in part tolerances between the nozzle array and substrate.