Low cost piezo printhead based on microfluidics in printed circuit board and screen-printed piezoelectrics
View Patent ↗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.
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 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.
5. The printhead according to claim 4 wherein the first base layer and second base layer are connected together through the use of an adhesive.
6. The printhead according to claim 5 wherein the adhesive is an adhesive sheet with portions cut out to minimize adhesive entering the internal fluidic passage.
7. 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.
8. 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.
9. The printhead according to claim 8 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.
10. 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.
11. 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.
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 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.
16. The printed circuit board according to claim 15 wherein operation of the fluidic actuator arrangement is controlled by an externally located control circuit, connected to the printed circuit board by external connections.
17. The printed circuit board according to claim 15 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.