Micro-electromechanical nozzle arrangement with non-wicking roof structure for an inkjet printhead

• US 7,438,391 B2
• Filed: 12/27/2007
• Issued: 10/21/2008
• Est. Priority Date: 06/09/1998
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, McAvoy, Gregory John
• Primary Examiner(s): Do; An H
• Application Number:
  US11/965,722
• Publication Number:
  US 20080117261A1
• Time in Patent Office: 299 Days
• Field of Search: 347/54, 347/65
• 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

The invention relates to a micro-electromechanical nozzle arrangement for an inkjet printhead. The nozzle arrangement includes a substrate defining an inverted pyramidal ink chamber with an ink supply channel leading through the substrate, the substrate having a layer of drive circuitry. The arrangement also includes a roof structure connected to the drive circuitry layer and covering the ink chamber, the roof structure defining a fluid ejection nozzle rim above said chamber in addition to ink flow guide rails to minimize wicking along the nozzle rim according to surface tension effects of ink in the chamber. Also included is a plurality of actuators displaceable with respect to, and radially spaced about, the nozzle rim, and in between, the guide rails, each actuator having a serpentine heater element configured to thermally expand upon receiving current from the drive circuitry thereby moving said actuators into the chamber operatively increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle.

Claims

1. A micro-electromechanical nozzle arrangement for an inkjet printhead, said arrangement comprising:

a substrate defining an inverted pyramidal ink chamber with an ink supply channel leading through the substrate, said substrate having a layer of drive circuitry;

a roof structure connected to the drive circuitry layer and covering the ink chamber, the roof structure defining a fluid ejection nozzle rim above said chamber in addition to ink flow guide rails to minimize wicking along the nozzle rim according to surface tension effects of ink in the chamber; and

a plurality of actuators displaceable with respect to, and radially spaced about, the nozzle rim, and in between, the guide rails, each actuator having a serpentine heater element configured to thermally expand upon receiving current from the drive circuitry thereby moving said actuators into the chamber operatively increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle.

2. The nozzle arrangement of claim 1, wherein each actuator is cantilevered to a heater element in a bendable manner.

3. The nozzle arrangement of claim 1, wherein the serpentine heater element is made from gold or copper.

4. The nozzle arrangement of claim 1, wherein the drive circuitry layer includes a CMOS layer.

5. The nozzle arrangement of claim 1, wherein the actuators are made from a polytetrafluoroethylene (PTFE) layer which sandwiches the heater element.

6. The nozzle arrangement of claim 1, wherein the ink supply channel is created by means of a deep silicon back edge of the substrate utilizing a plasma etcher.

7. The nozzle arrangement of claim 1, having a central arm which includes both metal and PTFE portions to provide structural support for the actuators.