The Development of a Prototype Silicon Nozzle Array for Continuous Ink Jet Printers

Abstract

The development of a prototype, micromachined silicon nozzle array with nine orifices per colour to be used in continuous ink jet printers is described. The nozzle array was anisotropically etched in <100> silicon using the {111} stop etch planes to define the walls resulting in recessed, truncated pyramid shaped nozzles. Each nozzle is extending about 30 μm from the surrounding surface. The wall of the extending part of the nozzle is approximately 7 μm thick. To attain the desired shape the silicon wafers were subjected to three consecutive etchings. The nine nozzles within a nozzle array are connected to a flow channel, which supplies the ink. After sawing of the wafer a glass lid is anodically bonded to each silicon die to seal the flow channel. The glass lid has pre-drilled holes that fit to each end of the flow channel thereby providing in- and outlet.A nozzle array with nine orifices (approximately 10*10μm) ejected jets at a velocity of approximately 45 m/s when a driving pressure of 18 bar was applied. The flow, for each of the nozzles, was measured to be around 0.22 ml/min. The nozzle array showed excellent droplet flight stability for all nozzles within the selected stimulation frequency range of 800 to 1200 kHz. The directivity error for the jets was measured in one dimension and the error was found to be below 4 mrad for all jets. It was possible to charge and deflect the jets individually