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US 2006/0221135 A1Published application
Self passivating transition metal nitride printhead heaters
AssigneeSilverbrook Research Pty Ltd
InventorsKia Silverbrook, Angus North, Gregory McAvoy, Jennifer Fishburn
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Abstract
A thermal inkjet printhead with heater elements formed from a self passivating transition metal nitride, but it oxidizes readily. By introducing an additive that allows the metal nitride to self passivate, the heater element forms a surface oxide layer, where the oxide has a low diffusion coefficient for oxygen so as to provide a barrier to further oxidation. With enhanced oxidation resistance, coatings to protect the heater from oxidative failure become unnecessary and the energy needed to form a bubble is reduced.
Claims17
An inkjet printhead comprising:
- a plurality of nozzles;
- a bubble forming chamber corresponding to each of the nozzles respectively, the bubble forming chambers adapted to contain ejectable liquid;
- and,
- a heater element disposed in each of the bubble forming chambers respectively, the heater element configured for heating some of the ejectable liquid above its boiling point to form a gas bubble that causes the ejection of a drop of the ejectable liquid from the nozzle;
- wherein,
- the heater element is formed from a transition metal nitride with an additive whose oxidation is thermodynamically favored above all other elements in the transition metal nitride, such that the heater element is self passivating.
3 more elements
Dependencies are inferred from the claim text.