MICROELECTROMECHANICAL STRUCTURE WITH ENHANCED REJECTION OF ACCELERATION NOISE

• US 20170322028A1
• Filed: 07/19/2017
• Published: 11/09/2017
• 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 10,209,071 B2
• Time in Patent Office: Days
• 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.

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.

7. The device of claim 1 wherein 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.

8. The device of claim 7, 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.

11. A device, comprising:

a substrate;

an anchor attached to the substrate;

a first pair of sensing masses coupled to the anchor aligned along a first axis;

a second pair of sensing masses coupled to the first pair of sensing masses and aligned along the first axis, a first one of the second pair of sensing masses being separated from a second one of the second pair of sensing masses by the first pair of sensing masses.

12. The device of claim 11, further comprising a third pair of sensing masses coupled aligned along the first axis.

13. The device of claim 12 wherein a first one of the third pair of sensing masses is spaced from a second one of the third pair of sensing masses by the second pair of sensing masses.

14. The device of claim 11, further comprising a rigid connector coupled between a first one of the first pair of sensing masses and a second one of the first pair of sensing masses.

15. The device of claim 11, further comprising a third pair of sensing masses coupled to the anchor and aligned with each other along a third axis that is transverse to the first axis.

16. A device, comprising:

a substrate;

an anchor attached to the substrate;

a first pair of sensing masses coupled to the anchor and aligned along a first axis;

a second pair of sensing masses coupled to the anchor and aligned along the first axis; and

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

17. The device of claim 16 wherein the third pair of sensing masses are aligned along a second axis that are transverse to the first axis.

18. The device of claim 16, further comprising a rigid coupling element coupled between ones of the first pair of sensing masses and coupled to the anchor.

19. The device of claim 18 wherein the rigid coupling element surrounds the anchor and is coupled to the anchor with a plurality of elastic elements.