MEMS resonator array structure

• US 7,595,708 B2
• Filed: 06/01/2007
• Issued: 09/29/2009
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Pan, Zhiyu, Partridge, Aaron, Lutz, Markus
• Primary Examiner(s): Summons; Barbara
• Application Number:
  US11/809,894
• Publication Number:
  US 20080218295A1
• Time in Patent Office: 851 Days
• Field of Search: 333/186, 333/197, 333/200, 310/309
• US Class Current: 333/186
• CPC Class Codes: H03H 2009/02354 applied along the periphery, e.g. at nodal points of the ring
• CPC Class Codes: H03H 2009/0244 Anchor loss
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02503 Breath-like, e.g. Lam? mode, wine-glass mode
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 2009/02527 Combined
• CPC Class Codes: H03H 3/0076 for obtaining desired frequency or temperature coefficients
• CPC Class Codes: H03H 9/02338 Suspension means
• CPC Class Codes: H03H 9/02448 of temperature influence
• CPC Class Codes: H03H 9/2405 of microelectro-mechanical resonators
• CPC Class Codes: H03H 9/2431 Ring resonators
• CPC Class Codes: H03H 9/462 Microelectro-mechanical filters
• CPC Class Codes: H03H 9/505 for microelectro-mechanical filters

Abstract

A MEMS array structure includes MEMS resonators that form an array. Each MEMS resonator includes beam sections. At least one of the beam sections of a first one of the MEMS resonators is a shared beam section that is also included in another of the MEMS resonators adjacent to the first MEMS resonator.

Claims

1. A MEMS array structure, comprising:

a plurality of MEMS resonators forming an array, each MEMS resonator including a plurality of beam sections, wherein at least one of the beam sections is a shared beam section that is also included in another of the plurality of MEMS resonators which is adjacent to the respective MEMS resonator.

2. The MEMS array structure of claim 1, wherein each MEMS resonator includes at least two shared beam sections.

3. The MEMS array structure of claim 1, wherein each MEMS resonator is square shaped and includes four beam sections.

4. The MEMS array structure of claim 3, where the shared beam mechanically couples the respective MEMS resonator to its adjacent MEMS resonator, the mechanical couplings of array causing the all of the plurality of MEMS resonators to vibrate in-plane and at a same frequency during operation of the array.

5. The MEMS array structure of claim 3, further comprising:

a substrate, wherein at least one corner section of at least one of the plurality of MEMS resonators includes a corresponding nodal point at which the array is anchored to the substrate.

6. The MEMS array structure of claim 5, further comprising:

an anchor configured to anchor the array to the substrate; and

an anchor coupling section connected one of at and near a corresponding one of the at least one nodal point and mechanically coupling the array to the anchor.

7. The MEMS array structure of claim 6, wherein the structure includes fewer anchors than nodal points.

8. The MEMS array structure of claim 6, further comprising:

a relief mechanism arranged to manage one of stress and strain on the substrate at a location of the anchor.

9. The MEMS array structure of claim 8, wherein the relief mechanism is a spring.

10. The MEMS array structure of claim 8, wherein the relief mechanism is disposed within the anchor coupling section and between the anchor and the corresponding one of the at least one nodal point.

11. The MEMS array structure of claim 6, wherein the corresponding one of the at least one nodal point is of an external corner section of the array.

12. The MEMS array structure of claim 5, further comprising:

an anchor located under a corresponding one of the at least one nodal point and configured to anchor the array to the substrate, wherein the corresponding one of the at least one nodal point is of an internal corner section of the array.

13. The MEMS array structure of claim 1, wherein the plurality of MEMS resonators are arranged so that, during operation, any two adjacent ones of the plurality of MEMS resonators vibrate 180 degrees out-of-phase relative to each other.

14. The MEMS array structure of claim 1, further including:

at least one sense electrode;

at least one drive electrode;

sense circuitry coupled to the at least one sense electrode; and

drive circuitry coupled to the at least one drive electrode;

wherein the at least one sense electrode and at least one drive electrode are located one of underneath and above the array.

15. The MEMS array structure of claim 14, wherein the at least one sense electrode provides at least one signal to the sense circuitry which, in response, provides a differential output signal.

16. The MEMS array structure of claim 14, wherein the at least one sense electrode provides at least one signal to the sense circuitry which, in response, provides a single ended output signal.

17. The MEMS array structure of claim 14, wherein the at least one sense electrode, the at least one drive electrode, the sense circuitry, and the drive circuitry provide output signals that are 180 degrees out-of-phase.

18. The MEMS array structure of claim 14, wherein the at least one drive electrode induces the plurality of beam sections to resonate.

19. The MEMS array structure of claim 14, wherein the at least one sense electrode and the at least one drive electrode are positioned relative to the plurality of beam sections so that at least one harmonic of the plurality of beam sections is detected.