Method of manufacture of a radiant plunger electromagnetic ink jet printer

• US 6,224,780 B1
• Filed: 07/10/1998
• Issued: 05/01/2001
• 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:
  US09/112,822
• Time in Patent Office: 1,026 Days
• Field of Search: 216/27, 347/54, 438/21
• 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 2/1635 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 2/16585 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: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 19/073 : Special arrangements for circuits, e.g. for protecting identification code in memory protection against unauthorised use of computer memory G06F12/14
• 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: G07F 7/08 : by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/086 : by passive credit-cards adapted therefor, e.g. constructive particularities to avoid counterfeiting, e.g. by inclusion of a physical or chemical security-layer for security documents G07D7/00; for the reading of record-carriers in general G06K7/00; for the design of coded credit-cards G06K19/10
• CPC Class Codes: G07F 7/12 : Card verification
• 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 radiant plunger 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 manufacture of a drop on demand ink jet print head 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) depositing and etching a first layer having a high saturation flux density on said electrical circuitry layer to define a first magnetic plate;

(d) 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;

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

(f) depositing and etching a sacrificial material layer in the region of said first magnetic plate and said coil, said etching including defining apertures for a series of spring posts;

(g) depositing and etching a second layer having a high saturation flux density so as to form an interconnected second magnetic plate, series of attached springs and spring posts to define an actuator for effecting ink ejection on demand;

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

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

(j) etching away any remaining sacrificial layers.

2. A method as claimed in claim 1 wherein said step (f) further comprises etching cavities defining a series of spring posts and said step (g) includes forming a series of leaf springs interconnected with said second magnetic plate for resiliently biasing said magnetic plate in a first direction.

3. A method as claimed in claim 1 wherein said conductive layer comprises substantially copper.

4. A method as claimed in claim 1 further including the step of depositing corrosion barriers over portions of said arrangement so as to reduce corrosion effects.

5. method as claimed in claim 1 wherein the etching of layers includes etching vias so as to allow for the electrical interconnection of portions of subsequent layers.

6. A method as claimed in claim 1 wherein said magnetic flux material comprises substantially a cobalt nickel iron alloy.

7. A method as claimed in claim 1 wherein said wafer comprises a double side polished CMOS wafer.

8. A method as claimed in claim 1 wherein step (j) is also utilised to simultaneously separate said wafer into separate print heads.