Ink jet printhead having a patternable ink channel structure

An ink jet printhead having an ink reservoir and a patternable ink channel structure, comprising:

• a heater plate having on one surface thereof an array of heating elements and interconnecting leads including contacts for the selective application of electrical pulses to each of the heating elements, each of the selectively applied pulses ejecting an ink droplet from the printhead;
• a passivation layer covering the heater plate surface and the interconnecting leads thereon, the heating elements and contacts being free of the passivation layer;
• a single patternable layer deposited directly on the passivation layer and patterned to expose the contacts and to form a reservoir groove and a plurality of parallel channel grooves therein, each of the plurality of parallel channel grooves having opposing ends and containing and exposing therein a heating element, one end of each of the plurality of parallel channel grooves being open and the opposing end being connected to the reservoir groove;
• and
• a non-opaque cover plate having an aperture, wherein the cover plate is bonded directly to the patternable layer to form a plurality of ink channels from the channel grooves, a reservoir portion from the reservoir groove, and nozzles from the open ends of the plurality of parallel channel grooves, and wherein the aperture in the cover plate being aligned with the reservoir portion to provide an ink inlet and another portion of the ink reservoir.

A method of fabricating an ink jet printhead, comprising the steps of:

• (a) providing a heater plate having on a first surface thereof an array of heating elements and interconnecting leads including contacts for the selective application of electrical pulses to each of the heating elements, each of the selectively applied pulses ejecting an ink droplet from the printhead;
• (b) depositing on the first surface of the heater plate a passivation layer, so that the heating elements and contacts are free of the passivation layer;
• (c) depositing on the passivation layer a patternable layer;
• (d) patterning the patternable layer to expose the contacts and to form a reservoir groove and a plurality of parallel channel grooves therein, so that each of the plurality of parallel channel grooves has opposing ends and one of the heating elements exposed therein, one end of each of the plurality of channel grooves being open and the opposing end of each of the plurality of channel grooves being connected to the reservoir groove;
• and
• (e) placing and bonding directly onto the patternable layer a cover plate having an aperture therein, with the aperture aligned with the reservoir groove.