Pressure sensing device with cavity and related methods

Patent metadata

Field	Value
Publication number	US-11808650-B2
Application number	US-202017063147-A
Country	US
Kind code	B2
Filing date	Oct 5, 2020
Priority date	Feb 19, 2015
Publication date	Nov 7, 2023
Grant date	Nov 7, 2023

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

What is claimed is:

1. A method, comprising:
experiencing, by a first pressure sensor in a pressure sensing system, an application of a first load by a first member in a structure on a second member in the structure, wherein the second member is positioned against the first member, and the first pressure sensor is carried in a first washer that is disposed between the first member and the second member;
detecting, by the first pressure sensor, a degree of a bending of a semiconductor die in the first pressure sensor, in response to the application of the first load;
generating, by a pressure sensing circuitry in the semiconductor die, a first output in accordance with the degree of the bending that is detected in the semiconductor die;
transmitting, by an integrated circuit (IC) interface in the semiconductor die, the first output to a first external antenna trace that is carried by a first substrate that is adjacent to the first pressure sensor; and
transmitting, by the first external antenna trace, the first output to an external system that monitors the pressure sensing system, wherein the first pressure sensor comprises:
the semiconductor die comprising an unsupported middle and two supported sides on either side of the unsupported middle, wherein the two supported sides are mounted on a support body; and
a cavity inside the first pressure sensor, wherein the cavity is disposed between the two supported sides, below the unsupported middle, and above the support body, wherein the IC interface comprises a transceiver circuit, and an internal antenna trace coupled to the transceiver circuit, and wherein the internal antenna trace is magnetically or electromagnetically coupled to the first external antenna trace, and wherein the internal antenna trace is disposed over an area where a supported side of the semiconductor die is mounted on the support body.

2. The method of claim 1 , wherein the semiconductor die comprises the pressure sensing circuitry, and the IC interface coupled to the pressure sensing circuitry, wherein the pressure sensing circuitry is disposed in the unsupported middle, and over a portion of the cavity.

3. The method of claim 2 , wherein the pressure sensing circuitry is configured to be responsive to the bending of the semiconductor die through the unsupported middle.

4. A method of manufacturing a sensing device, the method comprising:
having a first integrated circuit (IC) die comprising a first pressure sensing circuitry and a first IC interface coupled to the first pressure sensing circuitry, the first IC die being disposed between first and second parts positioned one against the other, the first IC interface comprising a first transceiver circuit, and first inner electrically conductive antenna traces coupled to the first IC interface, the first inner electrically conductive antenna trances being magnetically or electromagnetically coupled to first outer electrically conductive antenna traces;
attaching a first support body to the first IC die with a bonding layer to form a first cavity between the first IC die and the first support body, wherein the bonding layer supports peripheral regions of the first IC die with an unsupported central region of the first IC die disposed over the first cavity; and
encapsulating the first support body and the first IC die with an encapsulation material to form a ring shaped body to distribute a load applied between the first and second parts, the first pressure sensing circuitry being responsive to bending associated with the first cavity.

5. The method of claim 4 , wherein having the substrate comprises having a ring shaped portion and a first arm extension portion that extends beyond the first IC die and the ring shaped portion, and first outer electrically conductive antenna traces formed in the first arm extension portion disposed around the first inner electrically conductive antenna traces.

6. The method of claim 5 , wherein the first arm extension portion comprises a circular shape so that the first outer electrically conductive antenna traces are configured to define a magnetic dipole.

7. The method of claim 5 , wherein encapsulating the support body comprises encapsulating the first arm extension portion.

8. The method of claim 5 , further comprising:
having a second integrated circuit (IC) die comprising a second pressure sensing circuitry and a second IC interface coupled to the second pressure sensing circuitry; and
attaching a second support body to the second IC die with a second bonding layer to form a second cavity between the second IC die and the second support body, wherein the encapsulating comprises also encapsulating the second support body and the second IC die with the encapsulation material to form the ring shaped body, the second pressure sensing circuitry being responsive to bending associated with the second cavity.

9. The method of claim 8 , wherein having the substrate further comprises a second arm extension portion that extends beyond the second IC die and the ring shaped body in a different direction than the first arm extension portion.

10. The method of claim 1 , further comprising:
experiencing, by a second pressure sensor in a pressure sensing system, an application of a second load by a third member in a structure on a fourth member in the structure, wherein the third member is positioned against the fourth member, and the second pressure sensor is carried in a second washer that is disposed between the third member and the fourth member;
detecting, by the second pressure sensor, a degree of a bending of a semiconductor die in the second pressure sensor, in response to the application of the second load;
generating, by the second pressure sensor, a second output in accordance with the degree of the bending that is detected by the second pressure sensor; and
transmitting, by the second pressure sensor, the second output to the external system.

11. The method of claim 10 , wherein transmitting, by the first pressure sensor, the first output to the external system comprises:
transmitting, by the first pressure sensor, the first output to the second pressure sensor via a wire connecting the first pressure sensor to the second pressure sensor; and
transmitting, by the second pressure sensor, the first output to the external system.

12. The method of claim 1 , wherein the experiencing and the detecting are performed in a testing system comprising the first member and the second member, the first member comprising a rigid substrate, a load cell coupled to the rigid substrate, a ball joint coupled to the load cell, and a contact plate configured to apply a set pressure to a top surface of the first pressure sensor, the second member comprising a prober chuck positioned adjacent to a bottom surface of the first pressure sensor and configured to support the first pressure sensor.

13. The method of claim 4 , further comprising:
having a substrate mounted on a carrier substrate, the substrate comprising the first outer electrically conductive antenna traces;
before encapsulating the first support body and the first IC die, mounting the first support body on the carrier so that the first outer electrically conductive antenna traces are disposed around the first inner electrically conductive antenna traces; and
releasing the carrier substrate after the encapsulating.

14. The method of claim 4 , wherein attaching a first support body to the first IC die comprises attaching with a bonding layer.

15. A method of manufacturing a sensing device, the method comprising:
having a first integrated circuit (IC) die compris

Assignees

• St Microelectronics Srl

Inventors

• Pagani Alberto
• Ziglioli Federico Giovanni
• Murari Bruno

Classifications

• G01L5/0038 Primary

  applying a pushing force · CPC title

• F16B31/028

  with a load-indicating washer or washer assembly · 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

• 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

• G01L5/243

  using washers · CPC title