Integrated microelectromechanical gyroscope with improved driving structure

• US 10,168,154 B2
• Filed: 12/19/2014
• Issued: 01/01/2019
• Est. Priority Date: 12/24/2009
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Cazzaniga, Gabriele, Coronato, Luca
• Primary Examiner(s): Kwok, Helen
• Application Number:
  US14/578,255
• Publication Number:
  US 20170023363A1
• Time in Patent Office: 1,474 Days
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An integrated MEMS gyroscope, is provided with: at least a first driving mass driven with a first driving movement along a first axis upon biasing of an assembly of driving electrodes, the first driving movement generating at least one sensing movement, in the presence of rotations of the integrated MEMS gyroscope; and at least a second driving mass driven with a second driving movement along a second axis, transverse to the first axis, the second driving movement generating at least a respective sensing movement, in the presence of rotations of the integrated MEMS gyroscope. The integrated MEMS gyroscope is moreover provided with a first elastic coupling element, which elastically couples the first driving mass and the second driving mass in such a way as to couple the first driving movement to the second driving movement with a given ratio of movement.

Claims

1. A MEMS gyroscope, comprising:

a first mass that, in use, moves in a first direction along a first axis;

a second mass that, in use, moves in a second direction along a second axis, the second axis being transverse to the first axis;

a third mass that, in use, moves in the first direction;

a first elastic coupling element coupled to the first mass and the second mass, the first elastic coupling element, in use, pulls the second mass in the second direction in response to the first mass moving in the first direction; and

a second elastic coupling element coupled to the second mass and the third mass, the second elastic coupling element, in use, pulls the second mass in the second direction in response to the third mass moving in the first direction, the second mass, in use, moves in the second direction only in response to the first mass, the third mass, or both, moving in the first direction.

2. The gyroscope of claim 1, further comprising:

a fourth mass that, in use, moves in the second direction along the second axis; and

a third elastic coupling element coupled to the first mass and the fourth mass, the third elastic coupling element, in use, pulls the fourth mass in the second direction in response to the first mass moving in the first direction.

3. The gyroscope of claim 2 wherein the second mass and the fourth mass, in use, move towards and away from each other along the second axis in response to movement of the first mass.

4. The gyroscope of claim 2,

wherein the first mass and the third mass, in use, move towards and away from each other along the first axis;

and

wherein the gyroscope further comprises a fourth elastic coupling element coupled to the fourth mass and the third mass, the fourth elastic coupling element, in use, pulls the fourth mass in the second direction in response to the third mass moving in the first direction.

5. A device, comprising:

a substrate;

a driving assembly coupled to the substrate, the driving assembly having a first set of driving electrodes separated from a second set of driving electrodes;

a first pair of masses coupled to the driving assembly and positioned between the first set of driving electrodes and the second set of driving electrodes, the first pair of masses configured to be driven along a first axis in response to the driving assembly;

a second pair of masses configured to move along a second axis that is transverse to the first axis, the second pair of masses remaining uncoupled from the driving assembly;

a first elastic coupling element coupled to a first one of the first pair of masses and a first one of the second pair of masses;

a second elastic coupling element coupled to the first one of the first pair of masses and a second one of the second pair of masses;

a third elastic coupling element coupled to a second one of the first pair of masses and the first one of the second pair of masses; and

a fourth elastic coupling element coupled to the second one of the first pair of masses and the second one of the second pair of masses, the first, second, third, and fourth elastic coupling elements configured to move the second pair of masses in response to movement of the first pair of masses.

6. The device of claim 5 wherein the first pair of masses are configured to be driven in phase opposition and the second pair of masses configured to move in phase opposition in response to the movement of the first pair of masses.

7. The device of claim 6 wherein the first, second, third, and fourth elastic coupling elements are configured to cause the first pair and the second pair of masses to move synchronously.

8. The device of claim 5, further comprising:

a central anchorage region positioned between the first set and the second set of driving electrodes; and

a plurality of central elastic coupling elements, each mass of the first pair and second pair of masses being separately coupled to the central anchorage region with one of the plurality of central elastic coupling elements.

9. The device of claim 8 wherein the plurality of central elastic coupling elements are more radially internal with respect to the central anchorage region than the first, second, third, and fourth elastic coupling elements.

10. A MEMS gyroscope, comprising:

two or more driving electrodes;

a first mass configured to move with a first driving movement in a first direction in response to activation of the two or more driving electrodes, the first mass having a first corner;

a second mass configured to move with a second driving movement in a second direction in response to the first driving movement, the second direction being transverse to the first direction, the second mass having a second corner, the second mass being uncoupled from the two or more driving electrodes;

a first elastic coupling element coupled to the first corner of the first mass and to the second corner of the second mass, the first elastic coupling element configured to generate the second driving movement of the second mass from the first driving movement;

a third mass configured to move with the second driving movement in the second direction in response to the first driving movement, the third mass having a third corner, the first mass having a fourth corner that is spaced from the first corner; and

a second elastic coupling element coupled to the fourth corner of the first mass and the third corner of the third mass.

13. The device of claim 10, wherein the first elastic coupling element has a main extension along an axis that is inclined from the first direction less than 90 degrees.

11. A device, comprising:

a first mass;

a second mass not coupled to a driving electrode;

a third mass;

a fourth mass;

a first elastic coupling element coupled to the first mass and the second mass, the first elastic coupling element being configured to move the second mass in response to movement of the first mass;

a second elastic coupling element coupled to the first mass and the third mass, the second elastic coupling element being configured to move the third mass in response to movement of the first mass; and

a third elastic coupling element coupled to the fourth mass and the second mass, the third elastic coupling element being configured to move the second mass in response to movement of the fourth mass.

12. The device of claim 11, further comprising:

a fourth elastic coupling element coupled to the fourth mass and the third mass, the fourth elastic coupling element being configured to move the third mass in response to movement of the fourth mass.