MEMS DEVICE WITH IMPROVED SPRING SYSTEM

• US 20150316379A1
• Filed: 07/15/2015
• Published: 11/05/2015
• Est. Priority Date: 09/11/2009
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: SEEGER, Joseph, ANAC, Ozan
• Granted Patent: US 9,891,053 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5733 Structural details or topology
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass

Abstract

A system and method in accordance with an embodiment reduces the cross-axis sensitivity of a gyroscope. This is achieved by building a gyroscope using a mechanical transducer that comprises a spring system that is less sensitive to fabrication imperfection and optimized to minimize the response to the rotations other than the intended input rotation axis. The longitudinal axes of the first and second flexible elements are parallel to each other and parallel to the first direction

Claims

1. A MEMS device comprising:

a proof mass system, wherein the proof mass system includes a proof mass and a transducer;

wherein the transducer detects motion of the proof mass in a first direction in a plane in response to force;

wherein the proof-mass moves in the plane; and

a spring system comprising a first flexible element;

a rigid element and a second flexible element;

wherein the first flexible element;

the rigid element and the second flexible element are disposed in the plane;

wherein the rigid element is coupled to proof mass system via the first flexible element and the second flexible element is coupled to the rigid element, wherein the first flexible element and the second flexible element each have a longitudinal axis parallel to the first direction of motion.

2. The MEMS device of claim 1 wherein the transducer comprises capacitive sensors.

3. The MEMS device of claim 1 wherein the first flexible element and the second flexible element each has a midpoint aligned along an axis perpendicular to the first direction of motion.

4. The MEMS device of claim 1 wherein the first flexible element and the second flexible element are both coupled to the rigid element on a first side of the rigid element.

5. The MEMS device of claim 1 wherein the first flexible element is coupled to the rigid element on a first side of the rigid element and the second flexible element is coupled to the rigid element on an opposite side of the rigid element.

6. The MEMS device of claim 1 wherein the force is in response to gravity.

7. The MEMS device of claim 1 wherein the force is in response to acceleration of the MEMS device.

8. The MEMS device of claim 1 wherein the force is in response to a magnetic field.

9. The MEMS device of claim 1 wherein the force is a Coriolis force in response to angular velocity.

10. The MEMS device of claim 1 wherein the force is an electrostatic force.

11. A MEMS device comprising:

a proof mass; and

a spring system compliant in a first direction of motion, coupled to the proof mass, the spring system comprising a first flexible element;

a rigid element coupled to the first flexible element; and

a second flexible element coupled to the rigid element, wherein the first flexible element and the second flexible element each have a longitudinal axis parallel to the first direction of motion;

the proof-mass and spring system are disposed in a plane;

wherein the proof-mass moves in the first direction of motion in the plane in response to a force,

wherein the first flexible element and the second flexible element each has a midpoint aligned along an axis perpendicular to the first direction of motion.

12. The MEMS device of claim 11 wherein the force is in response to gravity.

13. The MEMS device of claim 11 wherein the force is in response to acceleration of the MEMS device.

14. The MEMS device of claim 11 wherein the force is in response to a magnetic field.

15. The MEMS device of claim 11 wherein the force is a Coriolis force in response to angular velocity.

16. The MEMS device of claim 11 wherein the force is an electrostatic force.