Method of manufacture of a tapered magnetic pole electromagnetic ink jet printer

• US 6,231,773 B1
• Filed: 07/10/1998
• Issued: 05/15/2001
• 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): Alanko, Anita
• Application Number:
  US09/113,125
• Time in Patent Office: 1,040 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 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2/14314 Structure of ink jet print heads with electrostatically actuated membrane
• 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 2/1639 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 2/16585 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: 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

A method of manufacturing an ink jet printhead includes providing a substrate. A doped layer is deposited on the substrate and is etched to create an array of nozzles on the substrate with a nozzle chamber in communication with each nozzle. Planar monolithic deposition, lithographic and etching processes are used to form a magnetically responsive plunger displaceably arranged relative to the nozzle chamber and an electromagnet which, when activated, causes displacement of the plunger towards a nozzle opening of the nozzle to effect ink ejection from the nozzle opening.

Claims

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

providing a substrate,

etching the substrate to form a nozzle chamber;

depositing a sacrificial layer in the nozzle chamber;

depositing a first permanent layer to form a magnetic field generating means;

depositing a second permanent layer to form a magnetically responsive plunger arranged displaceably arranged relative to the nozzle chamber and the magnetic field generating means;

etching the substrate to form a nozzle opening, wherein the plunger is displaced, when activated by the magnetic field generating means, towards a nozzle opening to effect ink ejection from the nozzle opening; and

removing the 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.

16. A method of manufacturing an ink jet printhead as claimed in claim 1 which includes forming the plunger as a hollow element with tapering side walls such that the effect, upon the plunger, of a magnetic field generated by the magnetic field generating means is to displace the plunger from a rest position towards the nozzle opening.

17. A method of manufacturing an ink jet printhead as claimed in claim 16 which includes forming an urging means on the plunger and the magnetic field generating means for returning the plunger to its rest position after removal of the magnetic field.

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) etching a nozzle chamber cavity in said wafer, said etching stopping substantially at said epitaxial layer;

(c) filling said nozzle chamber cavity with a first sacrificial material layer;

(d) depositing and etching a first layer having a high saturation flux density on said electrical circuitry layer to define a first magnetic plate;

(e) depositing and etching an insulating layer on said first layer and said electrical circuitry layer, said etching including etching vias for a subsequent conductive layer;

(f) depositing and etching a conductive layer on said insulating layer in the form of a conductive coil conductively interconnected with said first layer;

(g) depositing and etching a sacrificial material layer in the region of said first magnetic plate and said coil;

(h) depositing and etching a second layer having a high saturation flux density so as to form a second magnetic plate over said nozzle chamber surrounded by an annulus;

(i) depositing and etching an inert material layer interconnecting said second magnetic plate and said annulus in a resilient manner;

(j) etching the back of said wafer to said epitaxial layer;

(k) etching an ink ejection nozzle through said epitaxial layer interconnected with said nozzle chamber cavity; and

(l) etching away any remaining sacrificial layers.

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

9. 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.

10. 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.

11. A method as claimed in claim 7 wherein said magnetic flux material comprises substantially a cobalt nickel iron alloy.

12. A method as claimed in claim 7 wherein said inert material comprises silicon nitride.

13. A method as claimed in claim 7 wherein said second magnetic plate includes a tapered portion adjacent said nozzle chamber.

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

15. A method as claimed in claim 7 wherein at least step (1) is also utilised to simultaneously separate said wafer into separate printheads.