Method of fabricating an aperture plate for a roof-shooter type printhead

A method of fabricating a nozzle plate for a roofshooter type thermal ink jet printhead, comprising the steps of:

• a) etching a trough in a first planar surface of a silicon wafer by orientation dependent etching, said trough extending less than an entire thickness through said silicon wafer to define a bottom wall, a distance between said bottom wall and a second planar surface, opposite from said first planar surface of said silicon wafer, defining a thickness of a nozzle containing portion of said nozzle plate;
• b) placing an etch resistant mask on said bottom wall, said mask comprising a pattern defining a plurality of apertures thereon;
• and
• c) etching a plurality of nozzle defining apertures from said bottom wall between said bottom wall and said second planar surface of said silicon wafer by orientation dependent etching, said etching of said plurality of nozzles being a distinct, separate etching step from the etching which forms said trough.

A method of fabricating a roofshooter type thermal ink jet printhead comprising an aperture plate having a plurality of nozzles and a heater plate having a plurality of heating elements on a first planar surface thereof corresponding to the plurality of nozzles, the method comprising the steps of:

• a) etching a trough along a longitudinal axis of a first planar surface of a silicon wafer by orientation dependent etching, said trough including angled side walls and extending less than an entire thickness through said silicon wafer to define a bottom wall, a distance between said bottom wall and a second planar surface, opposite from said first planar surface of said silicon wafer defining a thickness of a nozzle containing portion of said aperture plate;
• b) placing an etch resistant mask on said bottom wall, said mask comprising a pattern defining a plurality of apertures thereon;
• c) etching a plurality of nozzle defining apertures in said bottom wall through said etch resistant mask, by orientation dependent etching, said apertures extending between said bottom wall and said second planar surface of said silicon wafer said etching of said plurality of nozzles being a distinct, separate etching step from the etching which forms said trough;
• d) etching said heater plate to provide an ink feed hole;
• and
• e) etching two grooves of a predetermined depth on said first planar surface of said heater plate, one groove being on each side of said heater elements along a longitudinal axis of said first planar surface, by orientation dependent etching, for mating with said side walls of said trough.