Method of forming an inkjet printhead using part of active circuitry layers to form sacrificial structures

• US 6,420,196 B1
• Filed: 10/19/1999
• Issued: 07/16/2002
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): LATTIN, CHRISTOPHER W
• Application Number:
  US09/425,194
• Time in Patent Office: 1,001 Days
• Field of Search: 438/21, 347/1, 347/20, 347/23, 347/26, 347/56, 347/9, 347/12, 347/32, 347/40, 347/47, 216/27
• US Class Current: 438/21
• CPC Class Codes: B41J 2/04518 reducing costs
• CPC Class Codes: B41J 2/04541 Specific driving circuit
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• 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 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• 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 2/1639 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

Abstract

An inkjet printhead is formed on a substrate incorporating drive circuitry for the nozzles of the printhead formed by a CMOS process. One or more of the layers formed by the CMOS process are utilized as a sacrificial material layer in forming the actuators or paddles of the ink ejection nozzles formed by MEMS process.

Claims

1. A method of fabricating an inkjet printhead, said method including the steps of:

fabricating electrical drive circuitry with layers of conductive, semi-conductive and non-conductive materials; and

forming a plurality of nozzle chambers on the layers of conductive, semi-conductive and non-conductive materials by the deposition and subsequent etching of a suitable integrated circuit fabrication material so that each nozzle chamber has an ink ejection aperture in a wall thereof;

wherein the method includes the steps of forming moveable actuators on the layers of conductive, semi-conductive and non-conductive materials so that each moveable actuator is operatively positioned with respect to one nozzle chamber and utilizing portions of at least one of the layers of conductive, semi-conductive and non-conductive materials as a sacrificial material and removing said portions to release each moveable actuator.

2. A method as claimed in claim 1 wherein the step of forming the moveable actuators includes the step of forming a moveable ink ejection paddle within each nozzle chamber.

3. A method as claimed in claim 1 wherein said step of utilizing portions of the conductive layer as said sacrificial material comprises the step of utilizing a CMOS metal layer.

4. A method as claimed in claim 2 wherein the step of forming said movable actuators includes the step of forming thermal actuators.

5. A method as claimed in claim 2 wherein said actuator is formed to be located external to said nozzle chamber and to be interconnected to said ink ejection paddle through an actuation interconnection aperture formed in a second wall of said nozzle chamber.

6. A method of fabricating an ink jet printhead, the method including the steps of:

carrying out an integrated circuit fabrication technique on a silicon wafer to form layers that define a drive circuitry component and sacrificial material with at least one layer that defines both part of the drive circuitry component and the sacrificial material;

fabricating a plurality of moveable actuators on the drive circuitry component and the sacrificial material;

forming a plurality of nozzle chambers on the layers by depositing and subsequently etching an integrated circuit fabrication material so that each actuator corresponds with a respective nozzle chamber; and

releasing each moveable actuator by etching away the sacrificial material.