Method of fabricating an injket printhead chip for use with a pulsating pressure ink supply

• US 7,147,791 B2
• Filed: 10/28/2003
• Issued: 12/12/2006
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Norton, Nadine
• Assistant Examiner(s): Tran, Binh X.
• Application Number:
  US10/693,978
• Publication Number:
  US 20040084405A1
• Time in Patent Office: 1,141 Days
• Field of Search: 216/27, 216/37, 216/58, 216/79
• US Class Current: 216/27
• CPC Class Codes: B41J 11/0005 Curl smoothing, i.e. smoothing down corrugated printing material, e.g. by pressing means acting on wrinkled printing material
• 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 2/1637 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 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• 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 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 : Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 : by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 : multi-dimensional coding
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 1/2112 : using still video cameras
• CPC Class Codes: H04N 1/2154 : the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 2101/00 : Still video cameras
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation
• CPC Class Codes: H04N 5/7458 : the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: Y10S 977/932 : for electronic or optoelectronic application

Abstract

A method of fabricating an ink jet printhead includes the step of depositing a layer of a sacrificial material on a substrate that incorporates drive circuitry layers positioned on a wafer substrate. The layer of sacrificial material is etched to define deposition zones for actuators. A first layer of a thermally expandable actuator material is deposited on the deposition zones. The first layer of actuator material and the drive circuitry layers are etched to define deposition zones for a conductive material of the actuators and for vias for heating circuits of the actuators. A layer of a conductive material is deposited on the first layer of actuator material. The layer of conductive material is etched to define a heating circuit for each actuator. A second layer of actuator material is deposited on the layer of conductive material so that the heating circuits are embedded in the actuator material. The actuator material is etched to define the actuators and the closure members. Nozzle chamber walls are formed with a suitable deposition and subsequent etching technique. The sacrificial layer is etched away to free each actuator and closure member. Ink channels are etched through the substrate so that each ink channel is in fluid communication with a respective nozzle chamber.

Claims

1. A method of fabricating an ink jet printhead chip for use with a pulsating pressure ink supply, the printhead chip having a substrate that incorporates drive circuitry layers, a plurality of nozzle arrangements, each nozzle arrangement having nozzle chamber walls that define a nozzle chamber and an ink ejection port in fluid communication with the nozzle chamber, a plurality of ink supply channels defined through the substrate to be in fluid communication with respective nozzle chambers and an actuator that is secured, at one end, with the substrate and arranged with respect to the nozzle chamber to drive a closure member on an opposite end of the actuator between an open position in which ink is ejected from the ink ejection port and a closed position in which ink is inhibited from being ejected, the method comprising the steps of:

depositing a layer of a sacrificial material on a substrate that incorporates drive circuitry layers positioned on a wafer substrate;

etching the layer of sacrificial material to define deposition zones for the actuators;

depositing a first layer of a thermally expandable actuator material on the deposition zones;

etching the first layer of actuator material and the drive circuitry layers to define deposition zones for a conductive material of the actuators and for vias for heating circuits of the actuators;

depositing a layer of a conductive material on the first layer of actuator material;

etching the layer of conductive material to define a heating circuit for each actuator;

depositing a second layer of actuator material on the layer of conductive material so that the heating circuits are embedded in the actuator material;

etching the second layer of actuator material to define the actuators and the closure members;

forming the nozzle chamber walls with a suitable deposition and subsequent etching technique;

etching away the sacrificial layer to free each actuator and closure member; and

etching the ink channels through the substrate so that each ink channel is in fluid communication with a respective nozzle chamber.

2. A method as claimed in claim 1, in which the second layer of actuator material is etched so that each closure member is positioned to close a respective ink inlet channel in its closed condition and to open the ink inlet channel in its open position.

3. A method as claimed in claim 1, in which the steps of depositing the first and second layers of actuating material include the steps of depositing first and second layers of polytetrafluoroethylene and the step of depositing the layer of conductive material includes the step of depositing copper.

4. A method as claimed in claim 1, in which the nozzle chamber walls are fabricated so that the actuators and the closures are each positioned within respective nozzle chambers.

5. A method as claimed in claim 1, in which the second layer of actuator material is etched so that each actuator is shaped so that, in a rest condition, the actuator encloses an arc, with each heating circuit being positioned so that when the actuator material is heated, differential thermal expansion of the actuator material causes the actuator to straighten at least partially and a subsequent cooling of the actuator material causes the actuator to return to its rest condition thereby displacing the closure member between the closed and open positions.

6. A method as claimed in claim 5, in which the layers of actuator material are etched so that each actuator defines a coil that partially uncoils when the actuator material undergoes differential thermal expansion.

7. A method as claimed in claim 5, in which the step of etching the conductive layer is such that each heating circuit includes a heater positioned proximate an inside edge of the conductive material and a return trace positioned outwardly of the heater, so that an inside region of the actuator material is heated to a greater extent with the result that the inside region expands to a greater extent that a remainder of the actuator material.

8. A method as claimed in claim 7, in which the step of etching the conductive layer is such that a serpentine length of conductive material defines each heater.