Method of manufacture of a permanent magnet electromagnetic ink jet printer

• US 6,267,905 B1
• Filed: 07/10/1998
• Issued: 07/31/2001
• 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): Gulakowski, Randy
• Assistant Examiner(s): Ahmed, Shamim
• Application Number:
  US09/113,108
• Time in Patent Office: 1,117 Days
• Field of Search: 216/2, 216/27, 438/21, 347/53, 347/54, 347/59, 298/900.9, 251/129.06, 251/129.15
• US Class Current: 216/27
• 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 2/1639 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 2/17596 Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 Electromagnetic transducer
• 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 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

Abstract

This patent describes a method of manufacturing a permanent magnet electromagnetic ink jet print head wherein an array of nozzles are formed on a substrate utilising planar monolithic deposition, lithographic and etching processes. Multiple ink jet heads are formed simultaneously on a single planar substrate such as a silicon wafer. The print heads can be formed utilising standard VLSI/ULSI processing and can include integrated drive electronics formed on the same substrate. The drive electronics preferably being of a CMOS type. In the final construction, ink can be ejected from the substrate substantially normal to the substrate plane.

Claims

1. A method of manufacturing an ink jet printhead which includes:

providing a substrate with a solenoid layer that is a magnetic field generating means;

etching said substrate to form a nozzle chamber of a nozzle;

depositing a sacrificial layer in said nozzle chamber;

depositing a first permanent layer on the sacrificial layer;

etching said first permanent layer to form a magnetically responsive plunger arranged in suspended relationship relative to the nozzle chamber, wherein the magnetic field generating means, when activated, causes displacement of the plunger towards a nozzle opening of the nozzle to effect ink ejection from the nozzle opening;

depositing a second permanent layer and etching said second permanent layer to form a suspension means attached to one surface of the plunger for suspending the plunger in position relative to the chamber and for returning the plunger to a rest position after deactivation of the magnetic field generating means; and

removing said sacrificial layer, thereby forming said printhead.

2. A method of manufacturing an ink jet printhead as claimed in claim 1 wherein multiple ink jet printheads are formed simultaneously on the substrate.

3. A method of manufacturing an ink jet printhead as claimed in claim 1 wherein said substrate is a silicon wafer.

4. A method of manufacturing an ink jet printhead as claimed in claim 1 wherein integrated drive electronics are formed on the substrate.

5. A method of manufacturing an ink jet printhead as claimed in claim 4 wherein said integrated drive electronics are formed using a CMOS fabrication process.

6. A method of manufacturing an ink jet printhead as claimed in claim 1 wherein ink is ejected from said substrate normal to said substrate.

7. A method of manufacture of an ink jet printhead arrangement including a series of nozzle chambers, said method comprising the steps of:

(a) providing an initial semiconductor wafer having an electrical circuitry layer and a buried epitaxial layer formed thereon;

(b) depositing and etching a first inert layer, said etching including etching predetermined vias and a nozzle chamber aperture;

(c) forming a first conductive coil layer on said first inert material layer around said nozzle aperture, said conductive coil layer including predetermined portions interconnecting with said electrical circuitry layer;

(d) utilizing said nozzle aperture to etch a nozzle chamber in said wafer;

(e) depositing and etching a sacrificial material layer over said wafer including said nozzle chamber, said etching including etching a mould for a series of magnet suspension posts and a permanent magnet above said nozzle aperture;

(f) depositing and etching a magnetic material layer, said magnetic material layer forming a permanent magnet above said nozzle aperture;

(g) depositing and etching an inert material layer interconnecting said permanent magnet with a series of spring posts in a resilient manner;

(h) back etching said wafer substantially to said buried epitaxial layer;

(i) etching a nozzle fluid ejection aperture through said buried epitaxial layer; and

(j) etching away said sacrificial layer.

8. A method as claimed in claim 7 wherein said conductive coil layer is formed by first depositing and etching a sacrificial layer forming a mould for said conductive coil layer.

9. A method as claimed in claim 7 wherein said conductive coil layer is formed utilizing chemical mechanical planarization.

10. A method as claimed in claim 7 wherein said first inert layer comprises substantially silicon nitride.

11. A method as claimed in claim 7 wherein said conductive coil layer comprises substantially copper.

12. A method as claimed in claim 7 further including the step of depositing corrosion barriers over portions of said arrangement so as to reduce corrosion effects.

13. A method as claimed in claim 7 wherein the etching of layers includes etching vias so as to allow for the electrical interconnection of portions of subsequent layers.

14. A method as claimed in claim 7 wherein said wafer comprises a double side polished CMOS wafer.

15. A method as claimed in claims 7 wherein at least step (j) is also utilised to simultaneously separate said wafer into separate printheads.