Ink jet printhead chip having an actuator mechanisms located about ejection ports

• US 20040080580A1
• Filed: 12/08/2003
• Published: 04/29/2004
• Est. Priority Date: 06/09/1998
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Granted Patent: US 6,966,633 B2
• Time in Patent Office: Days
• US Class Current: 347/54
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/1433 Structure of nozzle plates
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16 Production of nozzles
• 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 2/1637 molding
• 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 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14435 Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2002/14475 characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 : with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

An inkjet printhead chip includes a substrate that defines a plurality of ink supply channels. A drive circuitry layer is positioned on the substrate. A plurality of nozzle arrangements is positioned on the substrate. Each nozzle arrangement includes a nozzle chamber defined by the substrate. A roof structure is positioned over the nozzle chamber. The roof structure defines an ink ejection port. At least one actuator is positioned in the roof structure and is displaceable with respect to the substrate on receipt of an electrical current from the drive circuitry layer to reduce a volume of the nozzle chamber so that ink is ejected from the ink ejection port.

Claims

1. An inkjet printhead chip that comprises a substrate that defines a plurality of ink supply channels;

a drive circuitry layer that is positioned on the substrate; and

a plurality of nozzle arrangements that are positioned on the substrate, each nozzle arrangement including

a nozzle chamber defined by the substrate;

a roof structure positioned over the nozzle chamber, the roof structure defining an ink ejection port; and

at least one actuator that is positioned in the roof structure and is displaceable with respect to the substrate on receipt of an electrical current from the drive circuitry layer to reduce a volume of the nozzle chamber so that ink is ejected from the ink ejection port.

2. An inkjet printhead chip as claimed in claim 1, in which a number of actuators are positioned in each roof structure about the ink ejection port.

3. An inkjet printhead chip as claimed in claim 2, in which each actuator includes. an actuator arm that is connected to the drive circuitry layer and extends towards the ink ejection port, a heating circuit being embedded in the actuator arm to receive the electrical signal from the drive circuitry layer, the actuator arm being of a material that has a coefficient of thermal expansion sufficient to permit the material to perform work as a result of thermal expansion and contraction, the heating circuit being positioned so that the actuator arm is subjected to differential thermal expansion and contraction to displace the actuator arm towards and away from the respective ink supply channel.

4. An inkjet printhead chip as claimed in claim 3, in which each actuator arm is of polytetrafluoroethylene while each heating circuit is one of the materials in a group including gold and copper.

5. An inkjet printhead chip as claimed in claim 3, in which each actuator arm includes an actuating portion that is connected to the drive circuitry layer and an ink displacement member that is positioned on the actuating portion to extend towards the ink ejection port.

6. An inkjet printhead chip as claimed in claim 3, in which each roof structure includes a rim that defines the ink ejection port, the rim being supported above the respective ink inlet channel with support arms that extend from the rim to the drive circuitry layer, the actuator arms being interposed between consecutive support arms.

7. An inkjet printhead chip as claimed in claim 1, in which the drive circuitry layer is a CMOS layer.