Robust Inertial Sensors

• US 20160327392A1
• Filed: 12/30/2014
• Published: 11/10/2016
• Est. Priority Date: 12/30/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Michael Baus, Robert Bosch GmbH
• Inventors: Kim, Bonsang, Feyh, Ando, Graham, Andrew, O'Brien, Gary, Baus, Michael, Maier, Ralf, Koc, Mariusz
• Granted Patent: US 10,317,211 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0235 Accelerometers
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 7/0016 Protection against shocks or vibrations, e.g. vibration damping
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01D 5/241 by relative movement of capacitor electrodes
• CPC Class Codes: G01P 1/003 used for damping
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: G01P 2015/0882 for providing damping of vibrations
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap

Abstract

In one embodiment, a sensor includes a rigid wafer outer body, a first cavity located within the rigid wafer outer body, a first spring supported by the rigid wafer outer body and extending into the first cavity, a second spring supported by the rigid wafer outer body and extending into the first cavity, and a first sensor structure supported by the first spring and the second spring within the first cavity.

Claims

1. A sensor, comprising:

a rigid wafer outer body;

a first cavity located within the rigid wafer outer body;

a first spring supported by the rigid wafer outer body and extending into the first cavity;

a second spring supported by the rigid wafer outer body and extending into the first cavity; and

a first sensor structure supported by the first spring and the second spring within the first cavity.

2. The sensor of claim 1, wherein the first sensor structure includes an encapsulated sensor element located within a second cavity.

3. The sensor of claim 2, wherein:

the first cavity has a first pressure;

the second cavity has a second pressure; and

the first pressure is a different pressure from the second pressure.

4. The sensor of claim 2, further comprising:

a second sensor structure directly supported by the rigid wafer outer body.

5. The sensor of claim 2, further comprising:

a second sensor structure supported by the first spring and the second spring within the first cavity.

6. The sensor of claim 2, wherein:

the first spring has a first spring constant;

the second spring has a second spring constant; and

the first spring constant is different from the second spring constant.

7. The sensor of claim 2, further comprising:

at least one anchor; and

at least one third spring extending from the at least one anchor and supporting the rigid wafer outer body, the at least one third spring integrally formed with the at least one anchor and the rigid wafer outer body.

8. The sensor of claim 2, wherein:

the rigid wafer outer body includes a first portion of a silicon dioxide layer; and

a second portion of the silicon dioxide layer is located at a bottom portion of the first sensor structure.

9. The sensor of claim 2, further comprising:

at least one interconnect extending from the first sensor structure into the rigid wafer outer body and supported by the first spring.

10. The sensor of claim 9, wherein the at least one interconnect is embedded within the first spring.

11. A method of forming a sensor, comprising:

forming a first sensing structure;

forming a first spring, the first spring including a first portion forming a portion of a rigid outer body, and a second portion extending from the rigid outer body to the first sensing structure;

forming a second spring, the second spring including a third portion forming a portion of the rigid outer body, and a fourth portion extending from the rigid outer body to the first sensing structure; and

forming a cavity about the first sensing structure such that the first sensing structure is supported in the first cavity by the first spring and the second spring.

12. The method of claim 11, wherein forming the first sensor structure comprises:

releasing a sensor element within the first sensing structure; and

encapsulating the released sensor element.

13. The method of claim 12, further comprising:

establishing a first final pressure of the sensor assembly within the first cavity; and

establishing a second final pressure of the sensor assembly within the second cavity, wherein the first final pressure is a pressure different from the second final pressure.

14. The method of claim 12, further comprising:

supporting a second sensor structure with the rigid outer body.

15. The method of claim 14, wherein supporting the second sensor structure with the rigid outer body comprises:

supporting the second sensor structure directly with the rigid outer body.

16. The method of claim 14, wherein supporting the second sensor structure with the rigid outer body comprises:

supporting the second sensor structure with the rigid outer body through the first and second springs.

17. The method of claim 12, wherein:

forming the first spring comprises forming the first spring with a first thickness;

forming the second spring comprises forming the second spring with a second thickness; and

the first thickness is thicker than the second thickness, such that the first spring and the second spring have different spring constants.

18. The method of claim 12, further comprising:

forming at least one anchor; and

forming at least one third spring extending from the at least one anchor and supporting the rigid outer body, the at least one third spring integrally formed with the at least one anchor and the rigid outer body.

19. The method of claim 12, further comprising:

forming at least one interconnect extending from the first sensor structure into the rigid wafer outer body and supported by the first spring.

20. The method of claim 19, wherein forming the first spring comprises:

embedding the at least one interconnect within the first spring.