Printhead integrated circuit comprising resistive elements spaced apart from substrate

• US 7,976,131 B2
• Filed: 11/10/2009
• Issued: 07/12/2011
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Do; An H
• Application Number:
  US12/616,042
• Publication Number:
  US 20100053276A1
• Time in Patent Office: 609 Days
• Field of Search: 347/9, 347/17, 347/54, 347/56, 347/62, 347/65
• US Class Current: 347/62
• CPC Class Codes: B41J 2/04505 aiming at correcting alignment
• CPC Class Codes: B41J 2/04516 preventing formation of satellite drops
• CPC Class Codes: B41J 2/04518 reducing costs
• CPC Class Codes: B41J 2/0452 reducing demand in current or voltage
• CPC Class Codes: B41J 2/04528 aiming at warming up the head
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04553 detecting ambient temperature
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• CPC Class Codes: B41J 2/04565 detecting heater resistance
• CPC Class Codes: B41J 2/0457 Power supply level being detected or varied
• CPC Class Codes: B41J 2/04571 detecting viscosity
• CPC Class Codes: B41J 2/04585 controlling heads based on thermal bent actuators
• CPC Class Codes: B41J 2/04588 using a specific waveform
• CPC Class Codes: B41J 2/0459 Height of the driving signal being adjusted
• CPC Class Codes: B41J 2/04591 Width of the driving signal being adjusted
• CPC Class Codes: B41J 2/04593 Dot-size modulation by changing the size of the drop
• CPC Class Codes: B41J 2/04596 Non-ejecting pulses
• CPC Class Codes: B41J 2/04598 Pre-pulse
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/155 : for line printing
• CPC Class Codes: B41J 2/1623 : bonding and adhesion
• CPC Class Codes: B41J 2/1628 : dry etching
• CPC Class Codes: B41J 2/1629 : wet etching
• CPC Class Codes: B41J 2/1631 : photolithography
• CPC Class Codes: B41J 2/1632 : machining
• CPC Class Codes: B41J 2/1635 : dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1639 : sacrificial molding
• CPC Class Codes: B41J 2/1642 : thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1646 : thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 : Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2002/14491 : Electrical connection
• CPC Class Codes: B41J 25/005 : for serial printing movements superimposed to character- or line-spacing movements
• CPC Class Codes: G06K 15/102 : using ink jet print heads
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

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.

Claims

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.