Fluid ejection device, printhead, printer, and method for manufacturing the ejection device

Patent metadata

Field	Value
Publication number	US-2018281402-A1
Application number	US-201815884186-A
Country	US
Kind code	A1
Filing date	Jan 30, 2018
Priority date	Mar 28, 2017
Publication date	Oct 4, 2018
Grant date	—

Abstract

Ejection device for fluid, comprising a solid body including: first semiconductor body including a chamber for containing the fluid, an ejection nozzle in fluid connection with the chamber, and an actuator operatively connected to the chamber to generate, in use, one or more pressure waves in the fluid such as to cause ejection of the fluid from the ejection nozzle; and a second semiconductor body including a channel for feeding the fluid to the chamber, coupled to the first semiconductor body, in such a way that the channel is in fluid connection with the chamber. The second semiconductor body integrates a damping cavity over which extends a damping membrane, the damping cavity and the damping membrane extending laterally to the channel for feeding the fluid.

First claim

1 . An ejection device, comprising:
a body including:
a chamber configured to hold a fluid;
an ejection nozzle in fluidic communication with the chamber;
an actuator operatively coupled to the chamber to generate, in use, one or more pressure waves in the fluid to cause an ejection of the fluid from the ejection nozzle;
a fluidic path in fluidic communication with the chamber and configured to provide the fluid to the chamber; and
a damping cavity and a damping membrane suspended over the damping cavity, the damping cavity being arranged, at least in part, upstream from the fluidic path and configured to receive the fluid before the fluid is provided to the fluidic path.

2 . The ejection device according to claim 1 , wherein the body further includes an inlet hole fluidically coupled to the fluidic path, the damping membrane being arranged laterally to the inlet hole.

3 . The ejection device according to claim 1 , wherein the body includes:
a first structural element housing the chamber, the ejection nozzle, and the actuator, and a second structural element coupled to the first structural element, the fluidic path, the damping cavity, and the damping membrane being integrated in the second structural element.

4 . The ejection device according to claim 3 , wherein the second structural element is a monolithic body, the damping cavity being buried in the monolithic body and the damping membrane being integrated in the monolithic body.

5 . The ejection device according to claim 3 , wherein the second structural element has a first surface and a second surface opposite the first surface, the second surface facing towards the chamber of the first structural element, the damping membrane extending between the damping cavity and the first surface of the second structural element.

6 . The ejection device according claim 1 , wherein the damping membrane has a thickness between 0.5 μm and 50 μm.

7 . The ejection device according to claim 1 , comprising a filter integrated in the body and extending, at least in part, in the fluidic path.

8 . The ejection device according to claim 7 , wherein the filter has a lattice structure forming a plurality of apertures having sub-micrometric or micrometric dimensions.

9 . The ejection device according to claim 7 , wherein the filter and the damping membrane are formed, at least in part, of a same material, the material including one of:
glass, germanium, and silicon.

10 . The ejection device according to claim 1 , wherein the fluidic path includes:
a duct in direct fluidic communication with the chamber; and an inlet cavity extending laterally and coplanar to the damping cavity, the inlet cavity being in fluidic connection with the duct; the inlet hole extending coplanar to the damping membrane and being in fluidic connection with the inlet cavity and offset with respect to the duct.

11 . The ejection device according to claim 10 , wherein the inlet cavity and the inlet hole form part of an inlet manifold of the ejection device.

12 . The ejection device according to claim 11 , further comprising an interface structure coupled with the body and defining a feed channel facing, at least in part, the damping membrane and in fluidic communication with the inlet hole,
the interface structure forming, along with the inlet cavity and the inlet hole, the inlet manifold of the ejection device.

13 . The ejection device according to claim 1 , wherein the damping cavity is in fluid communication with an environment external to the ejection device and configured to receive an environmental pressure of the external environment.

14 . The ejection device according to claim 1 , wherein the actuator comprises an actuation membrane operatively coupled to the chamber and a piezoelectric element located on the actuation membrane, wherein the piezoelectric element is controllable so as to cause a movement of the actuation membrane at least one of: towards the chamber and away from the chamber.

15 . A printhead, comprising:
a reservoir having a reservoir chamber configured to contain a fluid; a plurality of ejection devices, each ejection device including a body including:
a chamber configured to hold a fluid;
an ejection nozzle in fluidic communication with the chamber;
an actuator operatively coupled to the chamber to generate, in use, one or more pressure waves in the fluid to cause an ejection of the fluid from the ejection nozzle;
a fluidic path in fluidic communication with the chamber and configured to provide the fluid to the chamber;
a damping cavity in fluid communication with the fluidic path and configured to provide the fluid to the fluidic path; and
a damping membrane suspended over the damping cavity; and
a manifold structure between the reservoir and the plurality of ejection devices, wherein the manifold structure is configured to place the reservoir in fluidic communication with the plurality of ejection devices.

16 . A printer comprising the printhead according to claim 15 .

17 . A method for manufacturing an ejection device, the comprising:
forming in a body, a chamber configured to hold a fluid, an ejection nozzle in fluidic connection with the chamber, and an actuator operatively coupled to the chamber to generate, in use, one or more pressure waves in the fluid to cause an ejection of the fluid from the ejection nozzle; forming, in the body, a fluidic path in fluidic connection with the chamber configured to provide fluid to the chamber, and integrating, in the body, a damping cavity and a damping membrane suspended over the damping cavity, wherein damping membrane is located upstream from the fluidic path and configured to provide fluid to the fluidic path.

18 . The method according to claim 17 , further comprising forming, in the body, an inlet hole fluidically coupled to the fluidic path, the damping membrane being formed laterally to the inlet hole.

19 . The method according to claim 17 , wherein the body includes a first structural element and a second structural element coupled to the first structural element, wherein the chamber, the ejection nozzle, and the actuator are formed in the first structural element, and wherein the fluidic path, the damping cavity, and the damping membrane are integrated in the second structural element.

20 . The method according to claim 19 , wherein forming the damping cavity comprises:
forming first trenches inside a surface portion of a substrate of semiconductor material; etching through the first trenches to form a first open area in the substrate below the first trenches and in fluidic communication with the first trenches; growing, on the surface portion of the substrate, a first surface layer, forming, with the substrate, the second structural element and closing the trenches at the top; and heat treating the second structural element and forming the damping cavity buried in the second structural element.

21 . The method according to claim 20 , further comprising:
forming, above the first surface layer, an etching mask forming a lattice structure; forming a second surface layer above the etching mask; and etching, at said lattice structure, selective portions of the second surface layer and of the first surface layer not protected by the etching mask and forming part of the fluidic path and a filter integrated in the second structural element and in the fluidic path.

22 . The method according to claim 21 , wherein the filter is form

Assignees

• St Microelectronics Srl
• St Microelectronics Inc

Inventors

• Giusti Domenico
• Ferrera Marco
• Prelini Carlo Luigi
• Dodd Simon

Classifications

• B41J2/1626

  etching · CPC title

• B41J2002/14419

  Manifold · CPC title

• B41J2/1623

  bonding and adhesion · CPC title

• B41J2/1631

  photolithography · CPC title

• B41J2/161

  of film type, deformed by bending and disposed on a diaphragm · CPC title