Pressure sensing device with cavity and related methods

Patent metadata

Field	Value
Publication number	US-9939338-B2
Application number	US-201514626153-A
Country	US
Kind code	B2
Filing date	Feb 19, 2015
Priority date	Feb 19, 2015
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A pressure sensing device may include a body configured to distribute a load applied between first and second parts positioned one against the other, and a pressure sensor carried by the body. The pressure sensor may include a support body, and an IC die mounted with the support body and defining a cavity. The IC die may include pressure sensing circuitry responsive to bending associated with the cavity, and an IC interface coupled to the pressure sensing circuitry.

First claim

That which is claimed is:

1. A pressure sensing device for measuring pressure between two members positioned against each other, the pressure sensing device comprising:
a main body configured to distribute a load between the two members, the main body being arranged between the two members, the main body having an interior and an exterior; and
a pressure sensor carried in the interior of the main body, the pressure sensor comprising:
a support body, and
an integrated circuit (IC) die having an unsupported middle and two supported sides on either side of the unsupported middle, the two supported sides being mounted on the support body, and the IC die comprising a pressure sensing circuitry and an IC interface coupled to the pressure sensing circuitry;

wherein the IC interface comprises a transceiver circuit and an electrically conductive antenna trace coupled to the transceiver circuit;
wherein the two supported sides and the unsupported middle of the IC die with the support body define a cavity inside the pressure sensor between the IC die and the support body,
wherein the pressure sensing circuitry is positioned in the unsupported middle of the IC die, over a portion of the cavity that is one of a center and near the center of the cavity;
wherein the electrically conductive antenna trace is positioned over where a supported side of the IC die is mounted on the support body; and

wherein the pressure sensing circuitry is responsive to a bending of the IC die through the unsupported middle over the cavity.

2. The pressure sensing device of claim 1 , further comprising a plurality of additional electrically conductive antenna traces so that pressure information can be wirelessly transmitted from the pressure sensor.

3. The pressure sensing device of claim 1 , wherein the pressure sensor further comprises a bonding layer between the supported sides of the IC die and the support body, the bonding layer defining both sides of the cavity.

4. The pressure sensing device of claim 3 , wherein the bonding layer comprises a glass frit bonding material.

5. The pressure sensing device of claim 1 , wherein the support body comprises a ceramic material, a glass material, or a silicon material.

6. The pressure sensing device of claim 1 , wherein the main body further comprises a slot within the interior of the main body and encapsulation material; and wherein the pressure sensor is arranged inside the slot, the encapsulation material surrounding the pressure sensor and filling the slot around the pressure sensor.

7. The pressure sensing device of claim 1 , further comprising an additional pressure sensor, the additional pressure sensor being carried by the main body adjacent to the pressure sensor.

8. The pressure sensing device of claim 7 , further comprising two dummy sensors adjacent to one another and carried by the main body, together with the pressure sensor and the additional pressure sensor;
wherein a spacing between each of the two dummy sensors, the pressure sensor and the additional pressure sensor are equal around a perimeter of the main body, the spacing contributing to a more even distribution of the load around the perimeter of the main body.

9. The pressure sensing device of claim 1 , wherein the two members comprise a bolt and a plate, and the main body comprises a washer positioned between the bolt and the plate.

10. The pressure sensing device of claim 1 , wherein the main body includes a ring-shaped body, and wherein the pressure sensor is carried in the interior of the ring-shaped body.

11. A pressure sensing device for measuring pressure between two members positioned against each other, the pressure sensing device comprising:
a main body configured to distribute a load between the two members, the main body being arranged between the two members, the main body having an upper surface; and
a pressure sensor carried by the main body, the pressure sensor comprising:
a spacer layer on a surface of the main body, the spacer layer including two side sections extending above the upper surface of the main body with a space between the two side sections, the surface of the main body exposed between the two side sections defining a lower periphery of the space; and
an integrated circuit (IC) die over the spacer layer, the IC die having an unsupported middle and two supported sides on either side of the unsupported middle, the two supported sides of the IC die being mounted to the two side sections of the spacer layer, the unsupported middle of the IC die defining an upper periphery of the space, the supported sides of the IC die and the two side sections of the spacer layer defining both sides of the space, with the supported sides, the lower periphery and the upper periphery of the space defining an enclosed cavity inside the pressure sensor between the main body and the IC die;

wherein the IC die comprises a pressure sensing circuitry and an IC interface coupled to the pressure sensing circuitry, and the IC interface comprises a transceiver circuit and an electrically conductive antenna trace coupled to the transceiver circuit;
wherein the pressure sensing circuitry is positioned in the unsupported middle of the IC die, over a portion of the enclosed cavity that is one of a center and near the center of the enclosed cavity;
wherein the electrically conductive antenna trace is positioned over a side section of the spacer layer; and
wherein the pressure sensing circuitry is responsive to a bending of the IC die through the unsupported middle of the IC die over the enclosed cavity.

12. The pressure sensing device of claim 11 , wherein the spacer layer comprises a metallic material.

13. The pressure sensing device of claim 11 , wherein the electrically conductive antenna trace comprises a first electrically conductive antenna trace and a second electrically conductive antenna trace;
wherein the two supported sides comprise a first supported side and a second supported side; and
wherein the first electrically conductive antenna trace is positioned over the first supported side, and the second electrically conductive antenna trace is positioned over the second supported side.

14. The pressure sensing device of claim 13 , wherein the pressure sensor comprises a substrate adjacent to the IC die, the substrate comprising a plurality of additional electrically conductive antenna traces coupled to the transceiver circuit, to the first electrically conductive antenna trace, and to the second electrically conductive antenna trace.

15. The pressure sensing device of claim 14 , wherein the plurality of additional electrically conductive antenna traces surround the IC die.

16. The pressure sensing device of claim 14 , wherein the substrate is canted with respect to the IC die.

17. The pressure sensing device of claim 13 , further comprising:
a plurality of additional electrically conductive antenna traces coupled to the transceiver circuit, to the first electrically conductive antenna trace, and to the second electrically conductive antenna trace; and
an arm extension extending outwardly from the main body;
wherein the plurality of additional electrically conductive antenna traces are carried by the arm extension.

18. The pressure sensing device of claim 11 , wherein the main body comprises a slot and encapsulation material, the pressure sensor being arranged inside the slot, with the encapsulation material surrounding the pressure sensor and filling the slot around the pressure sensor.

19. A pressure sensing system for measuring

Assignees

• St Microelectronics Srl

Inventors

• Pagani Alberto
• Ziglioli Federico Giovanni
• Murari Bruno

Classifications

• G01L5/243

  using washers · CPC title

• G01L1/18

  using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material · CPC title

• G01L5/0038 Primary

  applying a pushing force · CPC title

• F16B31/028

  with a load-indicating washer or washer assembly · CPC title

• G01L1/20

  by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids (of piezo-resistive materials G01L1/18); by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress · CPC title