Inkjet printhead integrated circuit with optimized trace orientation

• US 7,401,895 B2
• Filed: 08/07/2006
• Issued: 07/22/2008
• 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): Nguyen; Thinh H
• Application Number:
  US11/499,741
• Publication Number:
  US 20060268048A1
• Time in Patent Office: 715 Days
• Field of Search: 347 40- 43, 347/5, 347/9, 347/12, 347 58- 59
• US Class Current: 347/42
• CPC Class Codes: B05D 2201/00 Polymeric substrate or laminate
• CPC Class Codes: B05D 3/08 by flames
• 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 2/04571 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 2/04591 Width of the driving signal being adjusted
• CPC Class Codes: B41J 2/04596 Non-ejecting pulses
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• 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 2/1626 etching
• 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 2002/14419 : Manifold
• CPC Class Codes: B41J 2002/14491 : Electrical connection
• CPC Class Codes: Y10T 29/49345 : Catalytic device making

Abstract

A printhead integrated circuit (IC) for an inkjet printer, with a plurality of nozzle chamber structures positioned on a wafer substrate to define nozzle chambers and an ink ejection nozzle in fluid communication with each nozzle chamber, has drive control and drive circuitry connectable to data and power supplies, and a plurality of elongate actuators attached to the substrate for displacement towards and away from the substrate in response to actuating signals from the drive control and drive circuitry. A plurality of ink ejection members are attached to respective actuators, each ejection member being positioned for acting on ink within respective nozzle chambers to eject a drop of ink from the ink ejection nozzle. The drive control and drive circuitry has traces between each actuator and the substrate and oriented transverse to a longitudinal axis of each respective actuator.

Claims

1. A printhead integrated circuit (IC) for an inkjet printer, the printhead IC comprising:

a wafer substrate;

a plurality of nozzle chamber structures positioned on the substrate to define nozzle chambers and an ink ejection nozzle in fluid communication with each nozzle chamber;

drive control and drive circuitry connectable to data and power supplies;

a plurality of elongate actuators attached to the substrate for displacement towards and away from the substrate in response to actuating signals from the drive control and drive circuitry; and

a plurality of ink ejection members attached to respective actuators, each ejection member being positioned for acting on ink within respective nozzle chambers to eject a drop of ink from the ink ejection nozzle, wherein

the drive control and drive circuitry has traces between each actuator and the substrate and oriented transverse to a longitudinal axis of each respective actuator.

2. A printhead IC according to claim 1, wherein the control and drive circuitry defines a plurality of transistors that are interposed between the substrate and corresponding actuators so that each actuator receives an electrical signal from one corresponding transistor.

3. A printhead IC according to claim 1, wherein each transistor comprises a poly layer having a plurality of the traces.

4. A printhead IC according to claim 1, wherein each elongate actuator includes an actuator arm of a laminated structure comprising a resiliently flexible inner layer, a conductive layer and a compensation layer, the inner layer being interposed between the conductive and compensation layers, the conductive layer being positioned between the inner layer and the substrate and defining an electrical heating circuit such that, when heated by an electrical current received from the associated transistor, the conductive layer expands and causes the actuator arm to bend away from the substrate, with subsequent cooling and contraction resulting in the actuator arm bending back towards the substrate.

5. A printhead IC according to claim 4, wherein the conductive layer defines a series of corrugations which are generally aligned with the traces.

6. A printhead IC according to claim 4, wherein each ink ejection member is a paddle that is connected to the conductive layer of the respective actuator, the conductive layer defining a discontinuity between the paddle and the heating circuit to insulate the paddle from the heating circuit.

7. A printhead IC according to claim 4, wherein the conductive layer and the compensation layer are of substantially the same material to compensate for stresses that are generated in the actuator arm as a result of reciprocal bending of the actuator arm.