Hewlett-packard Company

Mark A Buonanno

David R Thomas

Domingo A Figueredo

Arun K Agarwal

Todd A Cleland

Robert C Maze

The present invention provides an ink-jet printhead substructure highly thermally efficient and greatly simplified in both the method of manufacture and resulting structure. The printhead substructure of the present invention comprises a resistor formed on an insulated substrate, a single conductive layer that provides both the conductive bonding interconnect pads and the conductive traces for the substructure, a passivation layer and a cavitation barrier. The resistor, passivation layer and cavitation barrier may comprise a single graded layer. The graded thin-film structure provides the resistor, passivation and cavitation barrier components without creating abrupt layer interfaces thereby, improving printhead reliability and durability. Fabrication of the printhead substructure of the present invention requires only two or three lithographic masks and a minimized number of sputter source materials.

Thin-film printhead device for an ink-jet printer

An inkjet printing device employs an inkjet printhead with a plurality of drop generators to eject drops of ink. Each drop generator includes a planar heater resistor, a protection layer having a first heating surface on the heater resistor and a second heating surface entirely surrounding the first heater surface on the heater resistor, and an ink ejection nozzle. The drop generator vaporizes ink at the first heating surface and ejects a drop of ink of a first mass from the nozzle when a first range of energies is applied to the heater resistor. The drop generator vaporizes ink at the first heating surface and the second heating surface and ejects a drop of ink of a second mass from the nozzle when a second range of energies is applied to the heater resistor.

Variable drop mass inkjet drop generator

The present invention provides an ink-jet printhead substructure highly thermally efficient and greatly simplified in both the method of manufacture and resulting structure. The printhead substructure of the present invention comprises a resistor formed on an insulated substrate, a single conductor layer that provides both the conductive bonding interconnect pads and the conductive traces for the substructure, a passivation layer and a cavitation barrier. The resistor, passivation layer and cavitation barrier may comprise a single graded layer. The graded thin-film structure provides the resistor, passivation and cavitation barrier components without creating abrupt layer interfaces thereby, improving printhead reliability and durability. Fabrication of the printhead substructure of the present invention requires only two or three lithographic masks and a minimized number of sputter source materials.

A preferred nucleation site is established in an ink firing chamber for a thermal inkjet printhead. The cavitation barrier layer of the resistance heater substrate is created with particular surface discontinuities and a temperature profile which favor heterogeneous bubble nucleation in a predetermined area. The predetermined area is located essentially along the axis of the ink droplet expulsion orifice.

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Sunnyvale, CA, United States of America

Mark A Buonanno