Fluid-ejecting integrated circuit utilizing electromagnetic displacement
View Patent ↗A fluid ejecting integrated circuit includes a wafer substrate. A drive circuitry layer is positioned on the wafer substrate. A protective passivation layer is positioned on the drive circuitry layer. A nozzle chamber wall extends from the passivation layer and a roof wall is positioned on the nozzle chamber wall such that the nozzle chamber wall and the roof wall define a nozzle chamber and a fluid ejection port in fluid communication with the nozzle chamber. A fluid ejecting member overlies the passivation layer within the nozzle chamber and is configured to be displaced to eject fluid through the fluid ejection port. A pair of spaced apart electrodes is connected to the drive circuitry layer so that the drive circuitry layer can create a potential difference between the electrodes, with one of the electrodes fast with the fluid ejecting member to displace the fluid ejecting member as a result of the potential difference.
1. A fluid ejecting integrated circuit (IC), the IC comprising:
a wafer substrate, on which is provided a drive circuitry layer;
a nozzle chamber defined by chamber side walls and a roof wall provided on the chamber side walls, the nozzle chamber being provided on the wafer substrate;
a fluid ejecting member provided within the nozzle chamber between the upper surface of the nozzle chamber and the wafer substrate;
a support formation provided within the nozzle chamber and spaced inwardly away from side walls of the nozzle chamber, the support formation extending from the wafer substrate at a normal thereto and supporting the fluid ejecting member thereon;
a fluid inlet opening defined through the chamber side wall in a lower half thereof, the fluid inlet opening for providing fluid communication to the nozzle chamber from outside of the nozzle chamber;
a first planar electrode layered to the fluid ejecting member;
a second planar electrode layered on the wafer substrate; and
a projection provided on the first planar electrode on a side facing the second planar electrode, the projection for contacting the second planar electrode to prevent contact between the first planar electrode and the second planar electrode; wherein
the first and second planar electrode are operable to establish a potential therebetween,
the first planar electrode is adapted to deform towards the second planar electrode when a potential is established between the first and second planar electrodes, and
the fluid inlet opening is defined through the chamber side wall to effect communication of fluid into the nozzle chamber such that the fluid surrounds the fluid ejecting member and support formation.
2. A fluid ejecting IC as claimed in claim 1 , wherein the support formation is continuous and defines a sealed air chamber between the first and second planar electrodes.
3. A fluid ejecting IC as claimed in claim 1 , wherein the second planar electrode is coated with a plastic layer on a side facing the first planar electrode.
4. A fluid ejecting IC as claimed in claim 1 , wherein a layer of silicon nitride is provided on the first electrode.
5. A fluid ejecting IC as claimed in claim 1 , wherein the roof wall defines a raised rim which bounds the fluid ejection port.