Method of fabricating a printhead integrated circuit with a nozzle chamber in a wafer substrate

• US 7,413,671 B2
• Filed: 10/20/2006
• Issued: 08/19/2008
• 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): Ahmed; Shamim
• Application Number:
  US11/583,939
• Publication Number:
  US 20070034598A1
• Time in Patent Office: 669 Days
• Field of Search: 216/13, 216/27, 216/41, 438/21, 347/55, 347/65
• US Class Current: 216/27
• 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

A method of fabricating a printhead integrated circuit includes the step of forming a first layer of a polymeric material on a substrate that incorporates drive circuitry. A heater element is formed on the first layer of polymeric material to be connected to the drive circuitry. A second layer of a polymeric material is formed on the heater element and the first layer such that the heater element is embedded in polymeric material. The polymeric layers are etched to define a plurality of radially extending bridging portions which terminate in a nozzle rim and a plurality of actuators which each extend between a respective pair of adjacent bridging portions and each terminate in a free end proximal to the rim. The substrate is etched so that the substrate and the actuators define a nozzle chamber in fluid communication with an ink ejection port defined by the nozzle rim.

Claims

1. A method of fabricating a printhead integrated circuit, the method comprising the steps of:

forming a first layer of a polymeric material on a substrate that incorporates drive circuitry;

forming a heater element on the first layer of polymeric material to be connected to the drive circuitry;

forming a second layer of a polymeric material on the heater element and the first layer such that the heater element is embedded in polymeric material;

etching the polymeric layers to define a plurality of radially extending bridging portions which terminate in a nozzle rim and a plurality of actuators which each extend between a respective pair of adjacent bridging portions and each terminate in a free end proximal to the rim; and

etching the substrate so that the substrate and the actuators define a nozzle chamber in fluid communication with an ink ejection port defined by the nozzle rim.

2. A method as claimed in claim 1, in which the step of forming the first layer of polymeric material includes the steps of depositing a first layer of polytetrafluoroethylene and etching the first layer of polytetrafluoroethylene to define vias for the heater element.

3. A method as claimed in claim 2, in which the step of forming the heater element includes the steps of depositing, masking and etching metal on the first layer of polytetrafluoroethylene.

4. A method as claimed in claim 3, in which the step of forming the second layer of polymeric material includes the steps of depositing a second layer of polytetrafluoroethylene and etching the second layer of polytetrafluoroethylene.

5. A method as claimed in claim 1, in which the step of forming the second layer of polymeric material includes the step of forming ink-wicking prevention formations about the nozzle rim.

6. A method as claimed in claim 1, in which the step of etching the substrate includes the step of crystallographically etching the substrate on crystallographic planes such that the nozzle chamber tapers inwardly away from the polymeric layers.

7. A method as claimed in claim 1, which includes the step of back-etching the substrate to define an ink inlet passage in fluid communication with the nozzle chamber.