MICROELECTROMECHANICAL DEVICE INCORPORATING A GYROSCOPE AND AN ACCELEROMETER

• US 20160091528A1
• Filed: 12/09/2015
• Published: 03/31/2016
• Est. Priority Date: 09/12/2011
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: SIMONI, Barbara, VALZASINA, Carlo
• Granted Patent: US 10,598,690 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions

Abstract

A microelectromechanical device includes: a supporting structure; two sensing masses, movable with respect to the supporting structure according to a first axis and a respective second axis; a driving device for maintaining the sensing masses in oscillation along the first axis in phase opposition; sensing units for supplying sensing signals indicative of displacements respectively of the sensing masses according to the respective second axis; processing components for combining the sensing signals so as to: in a first sensing mode, amplify effects on the sensing signals of concordant displacements and attenuate effects of discordant displacements of the sensing masses; and in a second sensing mode, amplify effects on the sensing signals of discordant displacements and attenuate effects of concordant displacements of the sensing masses.

Claims

1. A device, comprising:

a first pair of masses aligned with each other along a first axis, each of the masses having a first end and a second end, the first pair of masses being configured to be driven;

a second pair of masses aligned with each other along a second axis that is transverse to the first axis, each of the masses having a first end and a second end;

a plurality of elastic coupling elements coupled between the first ends of the first pair of masses and the first ends of the second pair of masses, the second pair of masses being configured to move in response to the first pair of masses through the plurality of elastic coupling elements; and

a plurality of pairs of elastic suspension elements, each of the masses of the first pair and the second pair of masses being coupled to one of the pairs of elastic suspension elements at a location between the first end and the second end, the location being closer to the second end than the first end.

2. The device of claim 1, further comprising:

a substrate;

a plurality of pairs of fixed electrodes formed on the substrate; and

a plurality of pairs of movable electrodes formed on each of the masses of the first pair and the second pair of sensing masses, the movable electrodes aligned with the fixed electrodes.

3. The device of claim 2 wherein a respective pair of elastic suspension elements is positioned between a first movable electrode of each pair of movable electrodes and a second movable electrode of the same pair of movable electrodes.

4. The device of claim 2 wherein each mass is configured to rotate around an axis through the respective pair of elastic suspension elements.

5. The device of claim 1 wherein each mass includes a first sensing unit and a second sensing unit.

6. The device of claim 5 wherein the first sensing unit includes a pair of movable electrodes formed on a side of the mass that faces a substrate.

7. The device of claim 6, further comprising a plurality of fixed electrodes formed in the substrate aligned with the pairs of movable electrodes formed on the masses.

8. A device, comprising:

a substrate;

a first mass, a second mass, a third mass, and a fourth mass, each mass having a first end and a second end, each of the first ends being closer to a central area than each of the second ends, the first, second, third, and fourth mass being arranged in a cross configuration;

a plurality of elastic coupling elements, each elastic coupling element being positioned between the first ends of adjacent masses; and

a plurality of pairs of elastic suspension elements coupled to opposite sides of each mass and positioned a location closer to the second end than to the first end of each.

9. The device of claim 8, further comprising:

a plurality of pairs of fixed electrodes formed on the substrate; and

a plurality of pairs of movable electrodes formed on each of the masses, the movable electrodes aligned with the fixed electrodes.

10. The device of claim 9 wherein a respective pair of elastic suspension elements is positioned between a first movable electrode of each pair of movable electrodes and a second movable electrode of the same pair of movable electrodes.

11. The device of claim 8 wherein each mass includes a first sensing unit and a second sensing unit.

12. The device of claim 11 wherein the first sensing unit includes a pair of movable electrodes formed on a side of the mass that faces the substrate.

13. The device of claim 11 wherein the second sensing using extends from the second end of each mass.

14. The device of claim 13 wherein the second sensing unit includes comb-figured electrodes.

15. A system, comprising:

a first pair of masses aligned with each other along a first axis, each of the masses having a first end and a second end, the first pair of masses being configured to be driven;

a second pair of masses aligned with each other along a second axis that is transverse to the first axis, each of the masses having a first end and a second end;

a plurality of elastic coupling elements coupled between the first ends of the first pair of masses and the first ends of the second pair of masses, the second pair of masses being configured to move in response to the first pair of masses through the plurality of elastic coupling elements;

a plurality of pairs of elastic suspension elements, each of the masses of the first pair and the second pair of masses being coupled to one of the pairs of elastic suspension elements at a location between the first end and the second end, the location being closer to the second end than the first end; and

processing circuitry configured to drive the first pair of masses.

16. The system of claim 15, further comprising:

a plurality of pairs of fixed electrodes formed on the substrate; and

a plurality of pairs of movable electrodes formed on each of the masses, the movable electrodes aligned with the fixed electrodes, the plurality of pairs of fixed electrodes being configured to generate sensing signals.

17. The system of claim 16 wherein the processing circuitry is configured to receive the sensing signals and combine the sensing signals in a first sensing mode and a second sensing mode.