Radially actuated micro-electromechanical nozzle arrangement

• US 7,465,029 B2
• Filed: 02/04/2008
• Issued: 12/16/2008
• 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:
  US12/025,605
• Publication Number:
  US 20080143792A1
• Time in Patent Office: 316 Days
• Field of Search: 347/54, 347/65
• US Class Current: 347/54
• 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 2/1623 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 29/49401 Fluid pattern dispersing device making, e.g., ink jet

Abstract

This invention relates to a micro-electromechanical nozzle arrangement for an inkjet printhead. The arrangement includes a substrate having a layer of drive circuitry and defining an ink chamber with an ink supply channel etched through the substrate. 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. Also included is a plurality of actuators radially spaced about, and displaceable with respect to, the nozzle rim, each actuator configured to thermally expand upon receiving current from the drive circuitry thereby moving said actuators into the chamber and operatively increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle. The substrate defines a number of vias through which the drive circuitry is connected to the actuators.

Claims

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

a substrate having a layer of drive circuitry and defining an ink chamber with an ink supply channel etched through the substrate;

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; and

a plurality of actuators radially spaced about, and displaceable with respect to, the nozzle rim, each actuator configured to thermally expand upon receiving current from the drive circuitry thereby moving said actuators into the chamber and operatively increasing a fluid pressure inside the chamber to eject a drop of ink via the ejection nozzle, wherein the substrate defines a number of vias through which the drive circuitry is connected to the actuators.

2. The nozzle arrangement of claim 1, wherein the actuators are constructed from a material having a coefficient of thermal expansion such that the actuators can perform work during thermal expansion.

3. The nozzle arrangement of claim 2, wherein the actuators are manufactured from a polytetrafluoroethylene (PTFE) material and have internal serpentine copper cores connected to the drive circuitry via the vias.

4. The nozzle arrangement of claim 3, wherein the ink chamber includes an inverted pyramidal ink chamber with a vertex thereof terminating at the ink supply channel.

5. The nozzle arrangement of claim 4, wherein the ink supply channel is created by means of a deep silicon back etch of the substrate utilizing a plasma etcher.

6. The nozzle arrangement of claim 1, including a series of struts interspersed between the actuators to support the nozzle rim.

7. The nozzle arrangement of claim 6, wherein the struts include both metal and PTFE portions.