Method of producing pagewidth inkjet printhead
View Patent ↗A method of producing a pagewidth inkjet printhead includes forming a substrate having defined therein a nozzle chamber operable to receive and store a fluid, the chamber fed at one side by an inlet passage; forming a nozzle plate in-situ on the substrate to define a nozzle opening on an opposite side of the nozzle chamber to the inlet passage; and forming a heater element including an electrically conductive element between the nozzle opening and the inlet passage, the heater element formed such that the electrically conductive element is in direct contact with the fluid in the nozzle chamber. The heater element is cantilever supported at one end by the nozzle chamber. The electrically conductive element includes two major face, a first major face facing the nozzle opening, and a second major face facing the inlet passage, the first and second major faces both in direct contact with the fluid in the nozzle chamber.
1. A method of producing a pagewidth inkjet printhead, the method comprising:
forming a substrate having defined therein a nozzle chamber operable to receive and store a fluid, the chamber fed at one side by an inlet passage;
forming a nozzle plate in-situ on the substrate to define a nozzle opening on an opposite side of the nozzle chamber to the inlet passage; and
forming a heater element including an electrically conductive element between the nozzle opening and the inlet passage, the heater element formed such that the electrically conductive element is in direct contact with the fluid in the nozzle chamber, wherein
the heater element is cantilever supported at one end by the nozzle chamber, and
the electrically conductive element includes two major face, a first major face facing the nozzle opening, and a second major face facing the inlet passage, the first and second major faces both in direct contact with the fluid in the nozzle chamber.
2. The method of claim 1 , wherein the inlet passage, nozzle opening, and heater element are formed to facilitate a net dissipation of heat generated by the heater element via a flow of ink through the inlet passage and out through the nozzle opening, whereby thermal equilibrium within the nozzle chamber is maintained substantially solely via expulsion of ink through the nozzle opening.
3. The method of claim 1 , wherein the nozzle plate is formed in-situ on the substrate with a thickness of substantially between 2 to 2.5 microns.
4. The method of claim 1 , wherein the heater element is formed to require between substantially 120 nanojoules and substantially 400 nanojoules of heating energy to form said gas bubbles.
5. The method of claim 1 wherein the nozzle plate is configured to support the bubble forming liquid adjacent each nozzle opening.
6. The method of claim 1 wherein the nozzle plate is formed by chemical vapor deposition.
7. The method of claim 6 wherein the chemical vapor deposition is of silicon nitride.
8. The method of claim 7 wherein the chemical vapor deposition is of silicon dioxide.
9. The method of claim 7 wherein the chemical vapor deposition is of oxi-nitride.
10. The method of claim 1 , wherein the substrate comprises a plurality of nozzle chambers each corresponding to a respective nozzle opening, and the method further comprises the steps of disposing a plurality of said heater elements within each chamber on different respective layers.
11. The method of claim 1 , further comprising the step of substantially covering the heater element with a conformal protective coating, the coating of each heater element having been applied substantially to all sides of the heater element simultaneously such that the coating is seamless.