Method of manufacture of a bend actuator direct ink supply ink jet printer

• US 6,264,849 B1
• Filed: 07/10/1998
• Issued: 07/24/2001
• 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 KAREN
• Application Number:
  US09/112,769
• Time in Patent Office: 1,110 Days
• Field of Search: 216/27, 438/21, 347/54, 347/59
• 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 2/1635 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: 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 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 manufacture of a thermally actuated ink jet printer which ejects ink via the utilization of a thermal actuator device is disclosed comprising the steps of initially providing a silicon and circuitry wafer layer including electrical circuitry necessary for the operation of the thermal actuators on demand; depositing a first sacrificial layer on top of the silicon and circuitry wafer layer; forming a series of heater structure layers comprising the thermal actuator on top of the first sacrificial layer; depositing a second sacrificial layer on top of the heater structure layers, the second sacrificial layer including suitably etched portions for the forming of a nozzle chamber; depositing a nozzle chamber layer forming a nozzle chamber of the ink jet printer having an ink ejection port defined therein on top of the second sacrificial layer; back etching the silicon wafer layer to form an ink supply channel in a region underneath a moveable end of the thermal actuator; and etching the first and second sacrificial layer in addition to relevant portions of the circuitry layer, if any, so as to release the thermal actuator layers to provide for an operational ink jet printer nozzle supplied via the ink supply channel.

Claims

1. A method of manufacturing an ink supply print head which ejects ink via the utilization of thermal actuator devices, the method comprising the steps of:

(a) providing a silicon and circuitry wafer layer including electrical circuitry necessary for the operation of thermal actuator devices on demand;

(b) depositing a first sacrificial layer on top of the silicon and circuitry wafer layer;

(c) forming a series of heater structure layers defining the thermal actuator devices on top of the first sacrificial layer;

(d) depositing a second sacrificial layer on top of the heater structure layers, the second sacrificial layer including etched portions suitable for forming nozzle chambers;

(e) depositing a third sacrificial layer to define nozzle chambers, each nozzle chamber having an ink ejection port positioned above the second sacrificial layer;

(f) back etching the silicon wafer layer to form an ink supply channel in a region underneath a moving end of each thermal actuator; and

(g) etching the first and second sacrificial layers in addition to relevant portions of the silicon and circuitry wafer layer, to free the thermal actuator devices.

2. A method as claimed in claim 1 wherein the back etching of the wafer layer includes forming a single ink supply channel that supplies each of a plurality of nozzle chambers.

3. A method as claimed in claim 2, wherein the third sacrificial layer is formed so that the nozzle chambers each have side wall portions and a top wall portion, with the side wall portions dividing the ink supply channel into multiple supply channels.

4. A method as claimed in claim 1 wherein the heater structure layers are formed by the steps of:

(a) depositing a first expansive material layer having a first coefficient of thermal expansion on the first sacrificial layer;

(b) depositing a conductive heater layer on the first expansive material layer; and

(c) depositing a second expansive material layer having a second coefficient of thermal expansion on the conductive heater layer, the first coefficient of thermal expansion being greater than the second coefficient of thermal expansion.

5. A method as claimed in claim 4 wherein the conductive heater layer is formed by the steps of:

(a) forming suitable trenches in the first expansive material layer;

(b) depositing a conductive material over substantially the whole of the first expansive material layer;

(c) chemically and mechanically planarizing the conductive material so that the conductive heater layer remains.

6. A method as claimed in claim 5 wherein the conductive heater layer is formed from substantially pure gold.

7. A method as claimed in claim 1 wherein metal conductive lines are incorporated into the wafer layer to form a barrier to protect the wafer layer from unwanted etching by any sacrificial etchant utilized in etching the sacrificial layers.

8. A method as claimed in claim 1 wherein the back etching step is deep silicon trench etching of the wafer layer.

9. A method as claimed in claim 1 wherein the wafer layer is first passivated by depositing a passivation material on the wafer layer.

10. A method as claimed in claim 1 wherein the third sacrificial layer is formed to define a series of small etchant holes used in the etching of the other sacrificial layers.

11. A method as claimed in claim 1 wherein the third sacrificial layer is comprised substantially entirely of Silicon Nitride.

12. A method as claimed in claim 1 wherein the third sacrificial layer is formed to incorporate portions positioned on the heater structure layers to firmly clamp the heater structure layers to lower layers.

13. A method as claimed in claim 1 wherein the wafer layer comprises a double-sided polished CMOS wafer.

14. A method as claimed in claim 1 which includes a further step of separating the wafer layer into separate printhead chips.