MICROELECTROMECHANICAL STRUCTURE WITH ENHANCED REJECTION OF ACCELERATION NOISE

• US 20170059322A1
• Filed: 04/27/2016
• Published: 03/02/2017
• Est. Priority Date: 05/11/2009
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Coronato, Luca, Cazzaniga, Gabriele
• Granted Patent: US 9,739,613 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An integrated MEMS structure includes a driving assembly anchored to a substrate and actuated with a driving movement. A pair of sensing masses suspended above the substrate and coupled to the driving assembly via elastic elements is fixed in the driving movement and performs a movement along a first direction of detection, in response to an external stress. A coupling assembly couples the pair of sensing masses mechanically to couple the vibration modes. The coupling assembly is formed by a rigid element, which connects the sensing masses and has a point of constraint in an intermediate position between the sensing masses, and elastic coupling elements for coupling the rigid element to the sensing masses to present a first stiffness to a movement in phase-opposition and a second stiffness, greater than the first, to a movement in phase, of the sensing masses along the direction of detection.

Claims

1. A device, comprising:

a substrate;

an anchor attached to the substrate;

a first pair of sensing masses coupled to the anchor;

a second pair of sensing masses coupled to the anchor; and

a third pair of sensing masses coupled to the second pair of masses, the first pair of sensing masses are separated from each other by the anchor and aligned with each other on a first axis and the second pair of sensing masses are separated from each other by the anchor and aligned with each other on a second axis that is transverse to the first axis.

2. The device of claim 1 wherein the first and second pairs of sensing masses are rectangular and the third pair of sensing masses are C-shaped masses.

3. The device of claim 2 wherein the each of the masses of the second pair of sensing masses is coupled internally within one of the C-shaped masses.

4. The device of claim 1, further comprising a first pair of driving masses coupled to the first pair of sensing masses.

5. The device of claim 4, further comprising a second pair of driving masses coupled to the third pair of sensing masses.

6. The device of claim 5 wherein the third pair of sensing masses is between the second pair of sensing masses and the second pair of driving masses.

8. The device of claim 1, further comprising a first rigid frame coupled between the anchor and the first pair of sensing masses and coupled between the anchor and the second pair of sensing masses.

9. The device of claim 8, further comprising a second rigid frame coupled between the first rigid frame and the first and second pairs of sensing masses.

10. The device of claim 9, further comprising a first set of elastic coupling elements between the anchor and the first frame along the second axis and a second set of elastic coupling elements between the first frame and the second frame along the first axis.

7. (canceled)

11. A device, comprising:

a substrate;

an anchor on the substrate;

a rigid coupling element coupled to the anchor;

a first pair of sensing masses coupled to the rigid coupling element along a first axis; and

a second pair of sensing masses coupled to the second rigid coupling element along a second axis that is transverse to the first axis.

12. The device of claim 11, further comprising:

a first pair of driving masses coupled to the first pair of sensing masses; and

a second pair of driving masses coupled to the second pair of sensing masses.

13. The device of claim 12 wherein the rigid coupling element is spaced from the first pair of driving masses by the first pair of sensing masses and the rigid coupling element is spaced from the second pair of driving masses by the second pair of sensing masses.

14. The device of claim 13 wherein each of the masses of the first and second pairs of driving masses includes an opening and one of the masses from the first or second pair of sensing masses is positioned within the opening.

15. The device of claim 14, further comprising a third pair of sensing masses positioned between the second pair of driving masses and the second pair of sensing masses.

16. A device, comprising:

a substrate;

an anchor on the substrate;

a first rigid coupling element coupled to the anchor;

a first pair of sensing masses coupled to the first rigid coupling element along a first axis;

a second pair of sensing masses coupled to the second rigid coupling element along a second axis that is transverse to the first axis; and

a third pair of sensing masses coupled to the second pair of sensing masses.

17. The device of claim 16 wherein the first pair of sensing masses is configured to detect rotation about the second axis, the second pair of sensing masses is configured to detect rotation about the first axis, and the third pair of sensing masses is configured to detect rotation about a third axis that is transverse to the first and second axis.

18. The device of claim 16, further comprising a second rigid coupling element positioned around and coupled to the first rigid coupling element.