MEMS resonator array structure and method of operating and using same

• US 7,227,432 B2
• Filed: 06/30/2005
• Issued: 06/05/2007
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Partridge, Aaron, Lutz, Markus, Pan, Zhiyu
• Primary Examiner(s): Summons; Barbara
• Application Number:
  US11/172,143
• Publication Number:
  US 20070001783A1
• Time in Patent Office: 705 Days
• Field of Search: 333/186
• 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 plurality of mechanically coupled MEMS resonators that are arranged in an N×M MEMS array structure. Each MEMS resonators includes a plurality of straight (or substantially straight) elongated beam sections that are connected by curved/rounded sections. Each elongated beam section is connected to another elongated beam section at a distal end via the curved/rounded sections thereby forming a geometric shape (e.g., a rounded square). Further, each resonator is mechanically coupled to at least one other adjacent resonator of the array via a resonator coupling section. The resonator coupling sections may be disposed between elongated beam sections of adjacent resonators. The resonators, when induced, oscillate at the same or substantially the same frequency. The resonators oscillate in a combined elongating (or breathing) mode and bending mode; that is, the beam sections exhibit an elongating-like (or breathing-like) motion and a bending-like motion. The one or more of the resonators of the array structure may include one or more nodal points or areas (i.e., portions of the resonator that are stationary, experience little movement, and/or are substantially stationary during oscillation of the resonator/array) in one or more portions or areas of the curved sections of the structure. The nodal points are suitable and/or preferable locations to anchor the resonator/array to the substrate.

Claims

1. A MEMS array structure comprising:

a plurality of MEMS resonators, each MEMS resonator including;

a plurality of elongated straight beam sections wherein each beam section includes a first end and a second end;

a plurality of curved sections, wherein each curved section includes a first end and a second end, wherein each end of a beam section is connected to an associated end of one of the curved section to thereby form a geometric shape; and

one or more resonator coupling sections, wherein at least one resonator coupling section is disposed between each of the opposing elongated straight beam sections of adjacent MEMS resonators.

2. The MEMS array structure of claim 1 wherein at least one curved section of at least one of the plurality of MEMS resonators includes a nodal point and wherein the MEMS array structure further includes:

at least one anchor coupling section; and

a substrate anchor, coupled to the nodal point via the anchor coupling section, to secure the MEMS resonator to a substrate.

3. The MEMS array structure of claim 2 further including a stress/strain relief mechanism disposed within the anchor coupling section and between the substrate anchor and the nodal point.

4. The MEMS array structure of claim 1 wherein each MEMS resonator includes four elongated straight beam sections and four curved sections and wherein the geometric shape is a rounded square shape.

5. The MEMS array structure of claim 1 wherein at least one curved section of each MEMS resonator includes a nodal point and wherein the MEMS array structure further includes at least one anchor coupling section disposed between an associated nodal point and a substrate anchor and wherein the substrate anchor secures the MEMS resonator to a substrate.

6. The MEMS array structure of claim 5 further including a stress/strain relief mechanism disposed within the anchor coupling section and between the substrate anchor and the nodal point.

7. The MEMS array structure of claim 1 wherein each resonator coupling section includes voids to reduce the mass of the section.

8. The MEMS array structure of claim 1 wherein each resonator coupling section includes a filleted shape at the ends such that the ends of the resonator coupling section have a greater width than the middle of the resonator coupling section.

9. The MEMS array structure of claim 1 wherein each curved section of each MEMS resonator includes at least one nodal point.

10. The MEMS array structure of claim 9 wherein at least one nodal point of each MEMS resonator is connected to a substrate anchor via an associated anchor coupling section.

11. The MEMS array structure of claim 10 further including a plurality of stress/strain relief mechanisms disposed within an associated anchor coupling section and between an associated substrate anchor and an associated nodal point.

12. The MEMS array structure of claim 1 wherein at least one of the plurality of elongated straight beam sections of each MEMS resonator includes a plurality of slots disposed therein.

13. The MEMS array structure of claim 1 wherein at least one of the plurality of curved sections of each MEMS resonator includes a plurality of slots disposed therein.

14. The MEMS array structure of claim 1 wherein the width of each elongated straight beam section of the MEMS resonator is greater at the ends than in the center thereof.

15. A MEMS array structure comprising:

a plurality of MEMS resonators, each MEMS resonator including;

a plurality of elongated straight beam sections wherein each beam section includes a first end and a second end;

a plurality of curved sections, wherein each curved section includes a first end and a second end, wherein each end of a beam section is connected to an associated end of one of the curved section to thereby form a geometric shape; and

wherein at least one curved section includes a nodal point;

a plurality of resonator coupling sections, wherein at least one resonator coupling section is disposed between at least one pair of opposing elongated straight beam sections of adjacent MEMS resonators such that each MEMS resonator is connected to at least one adjacent MEMS resonator; and

a plurality of anchor coupling sections, wherein the at least one nodal point of each MEMS resonator is connected to a substrate anchor via an associated anchor coupling section.

16. The MEMS array structure of claim 15 further including a plurality of stress/strain relief mechanisms, wherein at least one stress/strain relief mechanism is disposed within an associated anchor coupling section and between the substrate anchor and the nodal point of the MEMS resonator.

17. The MEMS array structure of claim 15 wherein each MEMS resonator includes four elongated straight beam sections and four curved sections and wherein the geometric shape is a rounded square shape.

18. The MEMS array structure of claim 15 wherein each resonator coupling section includes voids to reduce the mass of the section.

19. The MEMS array structure of claim 15 wherein each resonator coupling section includes a filleted shape at the ends such that the ends of the resonator coupling section have a greater width than the middle of the resonator coupling section.

20. The MEMS array structure of claim 15 wherein at least one of the plurality of elongated straight beam sections of each MEMS resonator includes a plurality of slots disposed therein.

21. The MEMS array structure of claim 15 wherein at least one of the plurality of curved sections of each MEMS resonator includes a plurality of slots disposed therein.

22. The MEMS array structure of claim 15 further including:

a plurality of sense electrodes;

a plurality of drive electrodes, wherein the sense and drive electrodes are juxtaposed the plurality of elongated straight beam sections of the MEMS resonators; and

sense circuitry, coupled to the sense electrodes, to provide an output signal.

23. The MEMS array structure of claim 22 wherein the sense electrodes provide one or more signals to the sense circuitry which, in response, provides a differential output signal.

24. The MEMS array structure of claim 22 wherein the sense electrodes provide one or more signals to the sense circuitry which, in response, provides a single ended output signal.

25. A MEMS array structure comprising:

a plurality of MEMS resonators, each MEMS resonator including;

a plurality of elongated straight beam sections wherein each beam section includes a first end and a second end;

a plurality of curved sections, wherein each curved section includes a first end and a second end, wherein each end of a beam section is connected to an associated end of one of the curved section to thereby form a geometric shape; and

one or more resonator coupling sections, wherein each of the opposing elongated straight beam sections of adjacent MEMS resonators includes a resonator coupling section connected therebetween;

a plurality of sense electrodes;

a plurality of drive electrodes, wherein the sense and drive electrodes are juxtaposed one or more of the plurality of elongated straight beam sections of the MEMS resonators; and

sense circuitry, coupled to the sense electrodes, to provide an output signal.

26. The MEMS array structure of claim 25 wherein the sense electrodes provide one or more signals to the sense circuitry which, in response, provides a differential output signal.

27. The MEMS array structure of claim 25 wherein the sense electrodes provide one or more signals to the sense circuitry which, in response, provides a single ended output signal.

28. The MEMS array structure of claim 25 wherein at least one of the sense electrodes is disposed within the geometric shape of at least one of the MEMS resonators.

29. The MEMS array structure of claim 28 wherein the at least one of the sense electrode is juxtaposed a plurality of elongated straight beam sections of the at least one of the MEMS resonator.

30. The MEMS array structure of claim 25 wherein at least one curved section of at least one of the plurality of MEMS resonators includes a nodal point and wherein the MEMS array structure further includes:

at least one anchor coupling section; and

a substrate anchor, coupled to the nodal point via the anchor coupling section, to secure the MEMS resonator to a substrate.

31. The MEMS array structure of claim 30 further including a stress/strain relief mechanism disposed within the anchor coupling section and between the substrate anchor and the nodal point.

32. The MEMS array structure of claim 25 wherein each curved section of each MEMS resonator includes at least one nodal point and wherein at least one nodal point of each MEMS resonator is connected to a substrate anchor via an associated anchor coupling section.

33. The MEMS array structure of claim 32 further including a plurality of stress/strain relief mechanisms disposed within an associated anchor coupling section and between an associated substrate anchor and an associated nodal point.

34. The MEMS array structure of claim 25 wherein each resonator coupling section includes voids to reduce the mass of the section.

35. The MEMS array structure of claim 25 wherein each resonator coupling section includes a filleted shape at the ends such that the ends of the resonator coupling section have a greater width than the middle of the resonator coupling section.