Printhead integrated circuit comprising resistive elements spaced apart from substrate
View Patent ↗A printhead integrated circuit includes inkjet nozzle assemblies disposed on a substrate. Each nozzle assembly includes a nozzle chamber having a nozzle aperture and an actuator associated with the nozzle chamber. The actuator ejects an ink droplet from the nozzle aperture when a resistive element of the actuator is heated by an electrical current. The resistive element of the actuator is spaced apart from the substrate.
1. A printhead integrated circuit comprising a plurality of inkjet nozzle assemblies disposed on a substrate, each nozzle assembly comprising:
a nozzle chamber having a nozzle aperture; and
an actuator associated with said nozzle chamber for ejecting an ink droplet from said nozzle aperture when a resistive element of said actuator is heated by an electrical current;
wherein at least part of the resistive element is spaced apart from said substrate, and
wherein at least part of an upper surface and a lower surface of said actuator are in contact with ink contained in said nozzle chamber.
2. The printhead integrated circuit as claimed in claim 1 , wherein said substrate is comprised of silicon.
3. The printhead integrated circuit as claimed in claim 1 , wherein said substrate comprises one or more CMOS layers.
4. The printhead integrated circuit as claimed in claim 3 , wherein said one or more CMOS layers comprise a drive transistor for each actuator, each drive transistor providing an energy pulse to a respective resistive element.
5. The printhead integrated circuit as claimed in claim 4 , wherein said one or more CMOS layers comprise control logic for controlling each drive transistor.
6. The printhead integrated circuit as claimed in claim 3 , wherein said one or more CMOS layers are passivated with a passivation layer, and each nozzle chamber is disposed on said passivation layer.
7. The printhead integrated circuit as claimed in claim 6 , wherein said nozzle nozzle chamber is positioned to overlie at least one of a drive transistor and control logic contained in said one or more CMOS layers.
8. The printhead integrated circuit as claimed in claim 6 , wherein said actuator is electrically connected to an uppermost CMOS layer via one or more vias etched through said passivation layer.
9. The printhead integrated circuit as claimed in claim 1 , wherein said nozzle chamber contains at least part of said actuator.
10. The printhead integrated circuit as claimed in claim 1 , wherein said resistive element of said actuator is comprised of titanium nitride.
11. The printhead integrated circuit of claim 1 , wherein said actuator is moveable relative to said substrate.
12. An inkjet printhead comprising a plurality of printhead integrated circuits according to claim 1 .