Gyroscopes Using Surface Electrodes

• US 20100257934A1
• Filed: 04/09/2009
• Published: 10/14/2010
• Est. Priority Date: 04/09/2009
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Kiyama, Lennie K., Walmsley, Robert G., Hartwell, Peter George, Zhang, Wenhua
• Granted Patent: US 8,272,266 B2
• Time in Patent Office: Days
• US Class Current: 73/504.120
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames

Abstract

Gyroscopes using surface electrodes are provided. In this regard, a representative microelectromechanical systems (MEMS) gyroscope, among others, includes a top substrate and a bottom substrate. The top substrate includes an outermost structure that is open and enclosed and a first driving structure that is disposed within the outermost structure and includes first driving electrodes disposed on a bottom surface. The bottom substrate is disposed below the top substrate and includes second driving electrodes disposed on a top surface of the bottom substrate. The second driving electrodes are substantially aligned below the first driving electrodes such that a force can be applied to the first driving structure by an electrostatic force generated between the first and second driving electrodes. The first and second driving electrodes are also configured to provide a capacitance signal based on the movement of the first driving structure.

Claims

1. A microelectromechanical systems (MEMS) gyroscope comprising:

a top substrate including;

an outermost structure, the outermost structure being open and enclosed, and

a first driving structure disposed within the outermost structure, the first driving structure including first driving electrodes disposed on a bottom surface of the first driving structure; and

a bottom substrate disposed below the top substrate, the bottom substrate including second driving electrodes disposed on a top surface of the bottom substrate, the second driving electrodes substantially aligned below the first driving electrodes such that a force can be applied to the first driving structure by an electrostatic force generated between the first and second driving electrodes, where the first and second driving electrodes are further configured to provide a capacitance signal based on the movement of the first driving structure, the capacitance signal being generated based on the first driving structure moving relative to the second driving electrodes.

2. The MEMS gyroscope as defined in claim 1, wherein the first driving structure further includes first sensing electrodes disposed on a bottom surface of the first driving structure along at least one side wall of the first driving structure, the first sensing electrodes being aligned substantially parallel to the at least one side wall of the first driving structure, and

the bottom substrate further includes second sensing electrodes disposed on the top surface of the bottom substrate, the second sensing electrodes substantially aligned below the first sensing electrodes of the first driving structure, where the first and second sensing electrodes are configured to provide a capacitance signal based on the movement of the first driving structure, the capacitance signal being generated based on the first driving structure moving relative to the second sensing electrodes.

3. The MEMS gyroscope as defined in claim 2, wherein the first driving electrodes are disposed adjacent and perpendicular to the first sensing electrodes.

4. The MEMS gyroscope as defined in claim 2, wherein the top substrate further includes a second driving structure disposed within the outermost structure, the second driving structure adjacent to the first driving structure, the second driving structure including third driving electrodes disposed on a bottom surface of the second driving structure, and

the bottom substrate further includes fourth driving electrodes disposed on the top surface of the bottom substrate, the fourth driving electrodes substantially aligned below the third driving electrodes such that a force can be applied to the second driving structure by an electrostatic force generated between the third and fourth driving electrodes, where the third and fourth driving electrodes are further configured to provide a capacitance signal based on the movement of the second driving structure, the capacitance signal being generated based on the second driving structure moving relative to the fourth driving electrodes and fourth sensing electrodes.

5. The MEMS gyroscope as defined in claim 4, wherein the second driving structure further includes third sensing electrodes disposed on the bottom surface of the second driving structure, the third sensing electrodes being disposed adjacent and perpendicular to the third driving electrodes, and

the bottom substrate further includes fourth sensing electrodes disposed on the top surface of the bottom substrate, the fourth sensing electrodes substantially aligned below the third sensing electrodes of the second driving structure, where the third and fourth sensing electrodes are configured to provide a capacitance signal based on the movement of the second driving structure, the capacitance signal being generated based on the second driving structure moving relative to the fourth sensing electrodes.

6. The MEMS gyroscope as defined in claim 4, wherein the outermost structure includes a divider between the first driving structure and the second driving structure.

7. The MEMS gyroscope as defined in claim 1, further comprising a second driving structure disposed within the outermost structure and perpendicular to the first driving structure, the second driving structure including third driving electrodes disposed on a bottom surface of the second driving structure;

and

the bottom substrate further includes fourth driving electrodes disposed on the top surface of the bottom substrate, the fourth driving electrodes substantially aligned below the third driving electrodes.

8. The MEMS gyroscope as defined in claim 7, wherein a force can be applied to the second driving structure by an electrostatic force generated between the third and fourth driving electrodes, where the third and fourth driving electrodes are further configured to provide a capacitance signal based on the movement of the second driving structure, the capacitance signal being generated based on the second driving structure moving relative to the fourth driving electrodes.

9. The MEMS gyroscope as defined in claim 7, further comprising a first sensing structure disposed within the outermost structure and adjacent to the first and second driving structures, the first sensing structure including third sensing electrodes disposed on a bottom surface of the first sensing structure;

and

the bottom substrate further includes second sensing electrodes disposed on the top surface of the bottom substrate, the second sensing electrodes substantially aligned below the first sensing electrodes.

10. The MEMS gyroscope as defined in claim 1, further comprising a cap wafer, where cap wafer, the top substrate, and the bottom substrate are hermetically sealed to maintain a vacuum adjacent to the driving and sensing structures.

11. A microelectromechanical systems (MEMS) gyroscope comprising:

a top substrate including;

an outermost structure, the outermost structure being open and enclosed,

a first sensing structure disposed within the outermost structure, the first sensing structure including first sensing electrodes disposed on a bottom surface of the first sensing structure along at least one side wall of the first sensing structure, the first sensing electrodes being aligned substantially parallel to the at least one side wall of the first sensing structure, and

a first driving structure that is disposed within the first sensing structure, the first driving structure including first driving electrodes disposed on a bottom surface of the first driving structure; and

a bottom substrate disposed below the top substrate, the bottom substrate including second driving electrodes disposed on a top surface of the bottom substrate, the second driving electrodes substantially aligned below the first driving electrodes such that a force can be applied to the first driving structure by an electrostatic force generated between the first and second driving electrodes, where the first and second driving electrodes are further configured to provide a capacitance signal based on the movement of the first driving structure, the capacitance signal being generated based on the first driving structure moving relative to the second driving electrodes.

12. The MEMS gyroscope as defined in claim 11, wherein the first driving electrodes are disposed adjacent and perpendicular to the first sensing electrodes.

13. The MEMS gyroscope as defined in claim 11, wherein the bottom substrate further includes second sensing electrodes disposed on the top surface of the bottom substrate, the second sensing electrodes substantially aligned below the first sensing electrodes, where the first and second sensing electrodes are configured to provide a capacitance signal based on the movement of the first sensing structure, the capacitance signal being generated based on the first sensing structure moving relative to the second sensing electrodes.

14. The MEMS gyroscope as defined in claim 13, wherein the top substrate further includes a second driving structure disposed within the first sensing structure, the second driving structure opposite to the first driving structure, the second driving structure including third driving electrodes disposed on a bottom surface of the second driving structure;

and

the bottom substrate further includes fourth driving electrodes disposed on the top surface of the bottom substrate, the fourth driving electrodes substantially aligned below the third driving electrodes.

15. The MEMS gyroscope as defined in claim 14, wherein the first sensing structure includes a divider between the first driving structure and the second driving structure.

16. The MEMS gyroscope as defined in claim 14, wherein the top substrate further includes a center member disposed within the first sensing structure and between the first driving structure and the second driving structure.

17. The MEMS gyroscope as defined in claim 16, wherein the top substrate further includes a third driving structure and a fourth driving structure disposed within the first sensing structure, the third and fourth driving structures disposed perpendicular to the first and second driving structures, the center member disposed between the third and fourth driving structures, the third driving structure including fifth driving electrodes disposed on a bottom surface of the third driving structure, the fourth driving structure including sixth driving electrodes disposed on a bottom surface of the fourth driving structure;

and

the bottom substrate further includes seventh and eighth driving electrodes disposed on the top surface of the bottom substrate, the seventh driving electrodes substantially aligned below the fifth driving electrodes and the eighth driving electrodes substantially aligned below the sixth driving electrodes.

18. The MEMS gyroscope as defined in claim 13, wherein the top substrate further includes a second driving structure disposed within a second sensing structure, the second sensing structure disposed within the outermost structure and adjacent to the first sensing structure, the second driving structure including third driving electrodes disposed on a bottom surface of the second driving structure, the second sensing structure including third sensing electrodes disposed on a bottom surface of the second sensing structure along at least one side wall of the second sensing structure, the third sensing electrodes being aligned substantially parallel to the at least one side wall of the second sensing structure;

and

the bottom substrate further includes fourth driving electrodes and fourth sensing electrodes disposed on the top surface of the bottom substrate, the fourth driving electrodes substantially aligned below the third driving electrodes and the fourth sensing electrodes substantially aligned below the third sensing electrodes.

19. The MEMS gyroscope as defined in claim 18, wherein the outermost structure includes a divider between the first sensing structure and the second sensing structure.

20. The MEMS gyroscope as defined in claim 18, wherein the first sensing structure and the second sensing structure have a C-shape, the open ends of the first sensing structure and the second sensing structure being adjacent to each other.