Hermetic chamber with electrical feedthroughs

• US 20070107524A1
• Filed: 10/18/2006
• Published: 05/17/2007
• Est. Priority Date: 10/19/2005
• Status: Active Grant

• Current Assignee: St. Jude Medical Luxembourg Holdings Ii S.A.R.L.
• Original Assignee: CardioMEMS Incorporated
• Inventors: O'Brien, David, Allen, Mark, You, Liang, Courcimault, Christophe, Joung, Yeun-Ho
• Granted Patent: US 7,748,277 B2
• Time in Patent Office: Days
• US Class Current: 73/754
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm

Abstract

An exemplary pressure cavity is disclosed that is durable, stable, and biocompatible and configured in such a way that it constitutes pico to nanoliter-scale volume. The exemplary pressure cavity is hermetically sealed from the exterior environment while maintaining the ability to communicate with other devices. Micromachined, hermetically-sealed sensors are configured to receive power and return information through direct electrical contact with external electronics. The pressure cavity and sensor components disposed therein are hermetically sealed from ambient pressure in order to reduce drift and instability within the sensor. The sensor is designed for harsh and biological environments, e.g., intracorporeal implantation and in vivo use. Additionally, novel manufacturing methods are employed to construct the sensors.

Claims

1. A device comprising:

a substrate having first and second sides;

a passage through the substrate from the first side to the second side;

a raised portion of the substrate located on the first side, surrounding the passage and having an outer surface area which forms an angle that is substantially 90 degrees or less relative to a plane defined by the surface of the first side and extending away from a center line of the passage; and

a metal layer disposed against the first side of the substrate over the passage;

wherein a compressive force is exerted on the raised portion that encircles the passage on the first side of the substrate; and

whereby an electrical device on the second side of the substrate can be placed in electrical communication with the compressive metal layer on the first side of the substrate through the passage.

2. The device of claim 1, wherein the metal layer is hermetically disposed against the first side of the substrate.

3. The device of claim 1, further comprising a conductive material located within the passage and in electrical contact with the metal layer, whereby an electrical device on the first side of the substrate can be placed in electrical communication with the conductive material on the second side of the substrate through the conductive material and the metal layer.

4. The device of claim 3, wherein the conductive material located within the passage is layer is hermetically disposed against sides of the substrate defining the cavity in the substrate.

5. The device of claim 3, further comprising an electrode located on the second side of the substrate, positioned over the passage and in electrical contact with the conductive material within the passage, whereby an electrical device on the first side of the substrate can be placed in electrical communication with the electrode on the second side of the substrate through the electrode, conductive material and metal layer.

6. A device comprising:

a housing having walls defining a chamber, a first one of the walls defining the chamber comprising an exterior wall of the housing;

a passage through the substrate from the first side to the second side;

a raised portion of the substrate located on the first side, surrounding the passage and having an outer surface area which forms an angle that forms an substantially 90 degrees or less relative to a plane defined by the surface of the first side and extending away from a center line of the passage; and

a metal layer disposed against the first side of the substrate over the passage;

wherein a compressive force is exerted on the raised portion that encircles the passage on the first side of the substrate; and

whereby an external electrical device can be placed in electrical communication with the electrode through the passage.

7. The device of claim 6, wherein the housing further comprises a unitary housing.

9. The device of claim 6, wherein the passage comprises a first passage, and wherein the device further comprises:

a second passage through the first one of the walls defining the chamber placing the chamber of the housing in communication with the ambient; and

a second electrode hermetically disposed over the second passage within the chamber, whereby the second passage is hermetically sealed;

whereby the chamber is hermetically sealed; and

whereby a second electrical feedthrough can be placed in electrical communication with the second electrode through the second passage.

10. The device of claim 9, wherein a second one of the walls defining the chamber and opposite the first wall comprises an exterior wall of the housing;

wherein the second one of the walls defining the chamber comprises a deflectable region;

wherein a third electrode is deposited on the second one of the walls within the chamber in the deflectable region; and

wherein the third electrode is placed in electrical communication with one of the first electrode or the second electrode.

11. The device of claim 10, wherein a third electrode is deposited on an interior wall of the chamber opposite to the first wall;

wherein the first, second, and third electrodes are electrically isolated from one another; and

wherein the interior wall of the chamber opposite to the first wall further comprises a deflectable region.

13. The device of claim 6, wherein the passage is completely filled with an electrically conductive material, whereby an external electrical device can be placed in electrical communication with the electrode by electrically connecting the electrical device to the electrically conductive material.

8. The of claim 8, wherein the housing is comprised of glass, fused silica, sapphire, quartz or silicon.

12. The device of claim 14, wherein a second one of the walls defining the chamber and opposite the first wall comprises an exterior wall of the housing;

wherein the second one of the walls defining the chamber comprises a deflectable region;

wherein at least one piezoresistor is deposited on the second one of the walls defining the chamber in the deflectable region thereof;

wherein the first electrode is in electrical contact with a first side of the piezoresistor; and

wherein the second electrode is in electrical contact with a second side of the piezoresistor.