Low cost piezo printhead based on microfluidics in printed circuit board and screen-printed piezoelectrics

• US 20060132543A1
• Filed: 12/20/2004
• Published: 06/22/2006
• Est. Priority Date: 12/20/2004
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Fitch, John S., Biegelsen, David K., Elrod, Scott A.
• Granted Patent: US 7,347,533 B2
• Time in Patent Office: Days
• US Class Current: 347/49
• CPC Class Codes: B41J 2/14233 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2002/14491 Electrical connection
• CPC Class Codes: B41J 2202/12 with ink circulating through the whole print head
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H05K 1/0272 Adaptations for fluid transport, e.g. channels, holes
• CPC Class Codes: H05K 2201/0394 Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/10083 Electromechanical or electro-acoustic component, e.g. microphone

Abstract

In accordance with one aspect of the present exemplary embodiment, a printhead includes a printed circuit board having at least one base layer, with at least one electrical trace, at least one fluidic passage and at least one fluidic chamber as part of the printed circuit board. The at least one electrical trace, fluidic passage and fluidic chamber are formed using printed circuit board manufacturing processes. An integrated circuit control chip is attached to the printed circuit board using known printed circuit board techniques. At least one fluidic actuator arrangement and aperture plate are attached to the printed circuit board using known PCB attachment processes.

Claims

1. A printhead comprising:

at least one printed circuit board having at least one base layer;

at least one electrical trace incorporated into the at least one base layer;

at least one fluidic passage incorporated into the at least one base layer;

at least one fluidic chamber incorporated into the at least one base layer,

wherein the at least one electrical trace, fluidic passage and fluidic chamber are formed using printed circuit board manufacturing processes;

at least one fluidic actuator arrangement connected to a first surface of the printed circuit board;

an aperture plate having at least one nozzle, connected to a second surface of the printed circuit board; and

a control circuit attached to one of the surfaces of the printed circuit board,

wherein the at least one fluidic actuator arrangement, the aperture plate and the control circuit are attached to the printed circuit board using printed circuit board manufacturing processes.

2. The printhead according to claim 1 wherein the printed circuit board is a multi-layered printed circuit board having more than one base layer.

3. The printhead according to claim 2 wherein the at least one fluidic passage is formed in more than one base layer of the base layers of the multi-layered printed circuit board.

4. The printhead according to claim 1 wherein all elements required to eject drops from the printhead are located on the printed circuit board when the printhead has fluid, and an external power source supplies power to the printhead.

5. The printhead according to claim 1 wherein the fluidic actuator arrangement includes at least one diaphragm and piezoelectric block with an electrode, wherein the piezoelectric block is bonded to the diaphragm, and the diaphragm is positioned and attached to the printed circuit board wherein upon activation of the diaphragm, fluid drops are emitted from the at least one nozzle.

6. The printhead according to claim 5 wherein an electrical connection is provided between the electrical trace and the piezoelectric electrode, and the electrical connection is at least one of an insulated thin film connection, a wire bond connection or a flip-chip connection.

7. The printhead according to claim 1 wherein the at least one fluidic passage is formed by etching a metal trace on the printer circuit board, and all sides of the fluidic passage are of metal.

8. The printhead according to claim 1 wherein the at least one fluidic passage is formed within the at least one base layer, and all sides of the fluidic passage is of the base layer material.

9. The printhead according to claim 2 wherein the fluidic passage is an internal fluidic passage, wherein a first base layer is a first portion of the fluidic passage and a second base layer is a second portion of the fluidic passage, and connection of the first base layer and the second base layer defines the internal fluidic passage.

10. The printhead according to claim 9 wherein the first base layer and second base layer are connected together through the use of an adhesive.

11. The printhead according to claim 10 wherein the adhesive is an adhesive sheet with portions cut out to minimize adhesive entering the internal fluidic passage.

12. The printhead according to claim 1 further including a filter screen positioned to filter fluid flowing in the printhead.

13. The printhead according to claim 1 further including a picture frame layer positioned to act as a guide for placement of the piezoelectric block.

14. The printhead according to claim 1, wherein the aperture plate is of a same material as the metal trace.

15. A method of forming a printhead comprising:

acquiring a printed circuit board having at least one base;

forming at least one electrical trace on the at least one base;

forming at least one fluidic passage on the at least one base;

forming at least one fluidic chamber on the at least one base;

connecting a fluidic actuator arrangement to the at least one base;

connecting an aperture plate to the at least one base; and

connecting a control chip to the at least one base,

wherein the electrical trace, fluidic passage, fluidic chamber, fluidic actuator arrangement, aperture plate, and control chip are formed or connected to the at least one base of the printed circuit board using printed circuit board processing techniques.

16. The method according to claim 15 wherein the step of acquiring the printed circuit board includes acquiring a printed circuit board having multiple bases, for a multi-layered circuit board.

17. The method according to claim 15 wherein the forming of the at least one fluidic passage includes forming the at least one fluidic passage in multiple layers of the multiple bases.

18. The method according to claim 17 wherein the forming of the at least one fluidic passage using adhesive to join separate bases containing parts of the fluidic passage, and wherein application of the adhesive is undertaken to minimize adhesive entry into the fluidic passage.

19. A printed circuit board designed with elements of a printhead formed or carried on the printed circuit board, the printhead comprising:

at least one base layer;

at least one electrical trace incorporated into the at least one base layer;

at least one fluidic passage incorporated into the at least one base layer;

at least one fluidic chamber incorporated into the at least one base layer,

wherein the electrical trace, fluidic passage and fluidic chamber are formed using printed circuit board manufacturing processes;

at least one fluidic actuator arrangement connected to a first surface of the printed circuit board; and

an aperture plate having at least one nozzle, connected to a second surface of the printed circuit board,

wherein the fluidic actuator arrangement and aperture plate are attached to the printed circuit board using printed circuit board manufacturing processes.

20. The printed circuit board according to claim 19 wherein operation of the fluidic actuator arrangement is controlled by an externally located control circuit, connected to the printed circuit board by external connections.

21. The printed circuit board according to claim 19 wherein the printed circuit board is a multi-layered printed circuit board having multiple bases, and the at least one electrical trace, fluidic passage and fluidic chamber are formed in selected ones of the multiple bases.