Method of manufacture of an inverted radial back-curling thermoelastic ink jet

• US 6,267,904 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: Skyerbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Gulakowski, Randy
• Assistant Examiner(s): Ahmed, Shamim
• Application Number:
  US09/112,830
• Time in Patent Office: 1,117 Days
• Field of Search: 216/27, 438/21, 347/54, 347/55
• 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 2/1628 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 2/1642 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: B41J 2002/14346 Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate
• 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: 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

A method of manufacturing an ink jet printhead which comprises the step of providing an initial semiconductor wafer having an electrical circuitry layer formed thereon. The circuitry layer is etched to define a nozzle cavity area. A first material layer is deposited and etched for vias through the first material layer for electrical interconnection of subsequently deposited layers with the circuitry layer. A conductive material layer is deposited on the first material layer and etched to form a heater pattern. A second material layer having a high coefficient of thermal expansion is deposited on the conductive material layer. The second material layer is etched to define an ink ejection port. The wafer is etched to define a nozzle chamber. An ink supply channel is etched through the wafer to be in fluid communication with the nozzle chamber.

Claims

1. A method of manufacturing an ink jet printhead said method comprising the steps of:

(a) providing an initial semiconductor wafer having an electrical circuitry layer formed thereon and etching the circuitry layer to define a nozzle cavity area;

(b) depositing a first material layer, said first material having a coefficient of thermal expansion that is such that a desired degree of expansion of the first material layer occurs when the first material layer is heated, and etching the first material layer for vias through the first material layer for electrical interconnection of subsequently deposited layers with the circuitry layer;

(c) depositing a conductive material layer on the first material layer, and etching the conductive material layer to form a heater pattern;

(d) depositing a second material layer on the conductive material layer, the second material layer having a coefficient of thermal expansion that is such that a desired degree of expansion of the second material layer occurs when the second material layer is heated and etching the second material layer to define a nozzle chamber rim, the deposition and etching of the first and second material layers being such that the first material layer is thicker than the second material layer, resulting in more movement of the second layer relative to the first layer, on heating of the first and second layers;

(e) etching the wafer to define an ink ejection port so that the ink ejection port is bounded by the first and second material layers and the conductive layer and a nozzle chamber so that the ink ejection port and the nozzle chamber are in fluid communication;

(f) etching the wafer about the ink ejection port to define thermal actuators that are radially spaced about the ink ejection port, each actuator including a portion of the first and second material layers and the conductive layer; and

(g) etching an ink supply channel through the wafer to be in fluid communication with the nozzle chamber.

2. A method as claimed in claim 1, which includes performing a crystallographic etch of the wafer to form the nozzle chamber, via slots defined between the thermal actuators.

3. A method as claimed in claim 2 wherein the crystallographic etch forms the nozzle chamber to have an inverted square pyramid shape.

4. A method as claimed in claim 1 wherein the ink supply channel is etched from a back surface of the wafer.

5. A method as claimed in claim 1 wherein at least one of the first material layer and the second material layer comprises substantially polytetrafluoroethylene.

6. A method as claimed in claim 1 wherein said conductive material layer comprises substantially gold, copper or aluminum.

7. A method as claimed in claim 1 which includes separating the wafer into separate printhead chips.