MICROELECTROMECHANICAL GYROSCOPE WITH COMPENSATION OF QUADRATURE ERROR DRIFT

• US 20160313123A1
• Filed: 07/01/2016
• Published: 10/27/2016
• Est. Priority Date: 10/30/2013
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: VALZASINA, Carlo, FALORNI, Luca Giuseppe
• Granted Patent: US 10,466,052 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames

Abstract

A microelectromechanical gyroscope, includes: a supporting body; a first movable mass and a second movable mass, which are oscillatable according to a first driving axis and tiltable about respective a first and second sensing axes and are symmetrically arranged with respect to a center of symmetry; first sensing electrodes and a second sensing electrodes associated with the first and second movable masses and arranged on the supporting body symmetrically with respect to the first and second sensing axis, the first and second movable masses being capacitively coupled to the respective first sensing electrode and to the respective second sensing electrode, a bridge element elastically coupled to respective inner ends of the first movable mass and of the second movable mass and coupled to the supporting body so as to be tiltable about an axis transverse to the first driving axis.

Claims

1. A device, comprising:

a substrate;

a first pair of masses;

a plurality of driving electrodes positioned within each of masses of the first pair of masses;

a second pair of masses;

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

a plurality of second elastic coupling elements positioned within the second pair of masses; and

a first pair and a second pair of sensing electrodes on the substrate, the electrodes of each of the first pair and the second pair of electrodes being spaced from each other by respective ones of the plurality of second elastic coupling elements.

2. The device of claim 1 wherein each of the masses of the first pair and the second pair are trapezoidal.

3. The device of claim 1, further comprising a third pair and a fourth pair of sensing electrodes on the substrate and aligned with the first pair of masses, the electrodes of each of the third pair and the fourth pair of electrodes being spaced from each other by respective ones of the plurality of driving electrodes.

4. The device of claim 1, further comprising a central support and a central anchor that couples the support to the substrate.

5. The device of claim 4 wherein the central support includes a plurality of extensions that extend into the masses of the first pair and second pair of masses.

6. A device, comprising:

a substrate;

a first, second, third, and fourth mass positioned above the substrate;

a central support structure including a first extension that extends into the first mass, a second extension that extends into the second mass, a third extension that extends in to the third mass, and a fourth extension that extends into the fourth mass.

7. The device of claim 6 wherein the central support has a rectangular shape, the first, second, third, and fourth extensions extending from sides of the rectangular shape.

8. The device of claim 7, further comprising:

a first spring coupled between the first extension and the first mass, the first spring being positioned within the first mass;

a second spring coupled between the second extension and the second mass, the second spring being positioned within the second mass;

a third spring coupled between the third extension and the third mass, the third spring being positioned within the third mass; and

a fourth spring coupled between the fourth extension and the fourth mass, the fourth spring being positioned within the fourth mass.

9. The device of claim 6, further comprising an anchor on the substrate and positioned centrally with respect to the first, second, third, and fourth masses and the central support coupled to the anchor.

10. A device, comprising:

a first trapezoidal mass;

a first plurality of driving electrodes coupled to the first mass;

a second trapezoidal mass;

a second plurality of driving electrodes coupled to the second mass;

a third trapezoidal mass positioned between the first and second masses;

a fourth trapezoidal mass positioned between the first and second masses;

a plurality of elastic coupling elements coupled to the first, second, third, and fourth masses, the plurality of elastic coupling elements configured to move the third and fourth masses in response to movement of the first and second masses by actuation of the driving electrodes.

11. The device of claim 10 wherein the first plurality of driving electrodes is positioned within the first mass and the second plurality of driving electrodes is positioned within the second mass.

12. The device of claim 10, further comprising a central rectangular support around which the first, second, third, and fourth masses are positioned.

13. The device of claim 12 wherein the central rectangular support includes a first extension that extends into the first mass, a second extension that extends into the second mass, a third extension that extends in to the third mass, and a fourth extension that extends into the fourth mass.

14. The device of claim 13, further comprising:

a first spring coupled between the first extension and the first mass, the first spring being positioned within the first mass;

a second spring coupled between the second extension and the second mass, the second spring being positioned within the second mass;

a third spring coupled between the third extension and the third mass, the third spring being positioned within the third mass; and

a fourth spring coupled between the fourth extension and the fourth mass, the fourth spring being positioned within the fourth mass.

15. The device of claim 14 wherein the first spring extends transverse to a direction of the first extension.