Patent ID: 6863375
Filing Date: 2005-03-08
Classification: B41J

Abstract:
1. An ejection device comprising: a nozzle plate comprising a silicon substrate having a first surface and a second surface; a plurality of first nozzle portions each having a circular cross-section, each of the first nozzle portions formed in the silicon substrate; a plurality of second nozzle portions each having a circular cross-section, each of the second nozzle portions formed on the second surface of the silicon substrate, and communicating with a corresponding first nozzle portion, the circular cross-section of each of the first nozzle portions being smaller than the circular cross-section of each of the second nozzle portions, the first and second nozzle portions forming nozzles each having a cross-section smaller stepwise from a rear end toward a front end of each nozzle; and a recess formed on the first surface of the silicon substrate, the recess having a flat bottom surface commonly communicating with the plurality of first nozzle portions such that the front end of each of the nozzles is exposed to the recess; and wherein the plurality of first and second nozzle portions are formed by applying dry-etching by plasma discharge to the second surface of the silicon substrate, and the recess is formed by applying wet-anisotropic-etching to the first surface of the silicon substrate.