Method of fabricating printhead IC to have displaceable inkjets

• US 7,326,357 B2
• Filed: 05/30/2006
• Issued: 02/05/2008
• 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:
  US11/442,126
• Publication Number:
  US 20060219656A1
• Time in Patent Office: 616 Days
• Field of Search: 216/13, 216/27, 216/41, 438/21, 347 55- 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 an inkjet printhead IC is provided which includes etching a circuitry layer to define first regions, depositing thermally expandable material thereover, etching the thermally expandable material and circuitry layer to define second regions having via holes, forming heaters at the second regions electrically contacting the circuitry layer through the via holes, depositing thermally expandable material on the heaters, forming a nozzle at each second region by etching the thermally expandable material to define an arm suspended at one end from the circuitry layer and an inkjet port in the suspended end, and forming channels aligned with the nozzles by etching a substrate carrying the circuitry layer. Each arm is formed to have one of the heaters embedded in the thermally expandable material such that uneven expansion is caused upon heating resulting in displacement of the arm and associated inkjet port relative to the circuitry layer.

Claims

1. A method of fabricating an inkjet printhead integrated circuit comprising the steps of:

etching a circuitry layer to define first regions;

depositing first thermally expandable material over the circuitry layer and the first regions;

etching the first thermally expandable material and the circuitry layer to define second regions having via holes;

forming heaters at the second regions electrically contacting the circuitry layer through the via holes;

depositing second thermally expandable material on the heaters;

forming a nozzle at each second region by etching the first and second thermally expandable material to define an arm suspended at one end from the circuitry layer and an inkjet port in the suspended end of the arm, each arm being formed to have one of the heaters embedded in the first and second thermally expandable material such that uneven expansion is caused upon heating resulting in displacement of the arm and associated inkjet port relative to the circuitry layer; and

forming channels aligned with the nozzles by etching a substrate carrying the circuitry layer.

2. A method as claimed in claim 1, wherein the first and second thermally expandable material is polytetrafluoroethylene.

3. A method as claimed in claim 1, wherein, in the nozzle forming step, the second thermally expandable material is etched so as to form a rim about each ink ejection port.

4. A method as claimed in claim 1, wherein the heater and nozzle forming steps are each performed plural times to form a plurality of heaters and nozzles at each second region.

5. A method as claimed in claim 1, wherein, in the channel forming step, crystallographic etching is performed.

6. A method as claimed in claim 1, wherein, in the channel forming step, back-etching is performed.

7. A method as claimed in claim 1, wherein the heater forming step comprises depositing and patterning a conductive material on the first thermally expandable material using a lift-off process.

8. A method as claimed in claim 7, wherein the conductive material is selected from the group containing gold and copper.