Angular rate sensor with in-phase drive and sense motion suppression

Patent metadata

Field	Value
Publication number	US-10760909-B2
Application number	US-201816010783-A
Country	US
Kind code	B2
Filing date	Jun 18, 2018
Priority date	Jun 18, 2018
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A MEMS device includes first, second, third, and fourth sense masses spaced apart from a surface of a substrate. A first drive coupler interconnects the first sense mass with a first actuator, a second drive coupler interconnects the second sense mass with a second actuator, a third drive coupler interconnects the third sense mass with a third actuator, and a fourth drive coupler interconnects the fourth sense mass with a fourth actuator. Each of the drive couplers includes a torsion bar having a length aligned parallel to an outer sidewall of an adjacent sense mass and first and second coupling links coupled to opposing first and second ends of the torsion bar. The first and second coupling links couple an adjacent one of the first, second, third, and fourth sense masses with a corresponding one of the first, second, third, and fourth actuators.

First claim

What is claimed is:

1. A device comprising:
a substrate having a planar surface;
a first sense mass, a second sense mass, a third sense mass and a fourth sense mass spaced apart from the planar surface of the substrate;
a first actuator, a second actuator, a third actuator, and a fourth actuator;
a first drive coupler interconnecting the first sense mass and the first actuator;
a second drive coupler interconnecting the second sense mass and the second actuator;
a third drive coupler interconnecting the third sense mass and the third actuator; and
a fourth drive coupler interconnecting the fourth sense mass and the fourth actuator,

wherein each of the first, second, third, and fourth drive couplers comprises:
a torsion bar having a length aligned parallel to an outer sidewall of an adjacent one of the first, second, third, and fourth sense masses;
a first coupling link coupled to a first end of the torsion bar; and
a second coupling link coupled to a second end of the torsion bar, the first and second coupling links coupling an adjacent one of the first, second, third, and fourth sense masses with a corresponding one of the first, second, third, and fourth actuators.

2. The device of claim 1 wherein:
the first and fourth sense masses are configured to be driven via the first and fourth actuators in a first drive direction parallel to a first axis oriented parallel to the planar surface;
the second and third sense masses are configured to be driven via the second and third actuators parallel to the first axis in a second drive direction that is opposite from the first drive direction;
the device is sensitive to angular velocity about a second axis oriented parallel to the planar surface of the substrate and perpendicular to the first axis;
the first and fourth sense masses are configured to move in a first sense direction parallel to a third axis oriented perpendicular to the planar surface of the substrate in response to the angular velocity of the device about the second axis; and
the second and third sense masses are configured to move in a second sense direction parallel to the third axis that is opposite from the first sense direction in response to the angular velocity of the device about the second axis.

3. The device of claim 1 wherein the length of the torsion bar is at least equivalent to an edge length of the outer sidewall of the corresponding one of the first, second, third, and fourth sense masses.

4. The device of claim 1 wherein the first, second, third, and fourth sense masses are configured to be driven parallel to a first axis oriented parallel to the planar surface, the device is sensitive to angular velocity about a second axis oriented parallel to the planar surface of the substrate and perpendicular to the first axis, and the torsion bar is oriented parallel to the second axis.

5. The device of claim 1 further comprising first, second, third, and fourth suspension structures configured to suspend the first, second, third, and fourth actuators in spaced apart relationship from the planar surface of the substrate, each of the first, second, third, and fourth suspension structures comprising:
a first anchor coupled to the planar surface of the substrate;
a second anchor coupled to the planar surface of the substrate, the first and second anchors being positioned proximate opposing first and second longitudinal edges of a corresponding one of the first, second, third, and fourth actuators;
a first spring structure interconnected between the first anchor and the first longitudinal edge of the corresponding one of the first, second, third, and fourth actuators; and
a second spring structure interconnected between the second anchor and the second longitudinal edge of the corresponding one of the first, second, third, and fourth actuators.

6. The device of claim 1 further comprising:
a first drive mode linkage;
a second drive mode linkage, the first and second drive mode linkages being located between the first and third sense masses, and interconnecting the first sense mass to the third sense mass;
a third drive mode linkage; and
a fourth drive mode linkage, the third and fourth drive mode linkages being located between the second and fourth sense masses, and interconnecting the second sense mass to the fourth sense mass.

7. The device of claim 6 wherein:
the first sense mass has a first sidewall facing a third sidewall of the third sense mass;
the second sense mass has a second sidewall facing a fourth sidewall of the fourth sense mass;
the first drive mode linkage comprises a first anchor coupled to the planar surface of the substrate, a first bar structure having a middle region coupled to the first anchor by a first spring beam, a second spring beam coupled between an end of the first bar structure and the first sidewall of the first sense mass, and a third spring beam coupled between an opposite end of the first bar structure and the third sidewall of the third sense mass;
the second drive mode linkage comprises a second anchor coupled to the planar surface of the substrate, a second bar structure having a middle region coupled to the second anchor by a fourth spring beam, a fifth spring beam coupled between an end of the second bar structure and the first sidewall of the first sense mass, and a sixth spring beam coupled between an opposite end of the second bar structure and the third sidewall of the third sense mass;
the third drive mode linkage comprises a third anchor coupled to the planar surface of the substrate, a third bar structure having a middle region coupled to the third anchor by a seventh spring beam, an eighth spring beam coupled between an end of the third bar structure and the second sidewall of the second sense mass, and a ninth spring beam coupled between an opposite end of the third bar structure and the fourth sidewall of the fourth sense mass; and
the fourth drive mode linkage comprises a fourth anchor coupled to the planar surface of the substrate, a fourth bar structure having a middle region coupled to the fourth anchor by a tenth spring beam, an eleventh spring beam coupled between an end of the fourth bar structure and the second sidewall of the second sense mass, and a twelfth spring beam coupled between an opposite end of the fourth bar structure and the fourth sidewall of the fourth sense mass, wherein each of the first, second, third, and fourth bar structures has a length that is aligned with a corresponding one of the first, second, third, and fourth sidewalls.

8. The device of claim 6 further comprising:
a first sense mode linkage located between the first and third sense masses, and interconnecting the first sense mass to the third sense mass; and
a second sense mode linkage located between the second and fourth sense masses, and interconnecting the second sense mass to the fourth sense mass.

9. The device of claim 8 wherein:
the first sense mode linkage is positioned between the first and second drive mode linkages; and
the second sense mode linkage being positioned between the third and fourth drive mode linkages.

10. The device of claim 8 wherein:
the first, second, third, and fourth sense masses are configured to be driven parallel to a first axis oriented parallel to the planar surface;
the first sense mode linkage comprises a first anchor coupled to the planar surface of the substrate, a first beam structure having a length that is aligned with the first axis and having a middle region coupled to the first anchor by a first flexure, a second flexure coupled between an end of the first beam structure and the first sidewall of the first sense mass, and a third flexure coupled between an opposite en

Assignees

• Nxp Usa Inc

Inventors

• Geisberger Aaron A

Classifications

• G01C19/5747 Primary

  each sensing mass being connected to a driving mass, e.g. driving frames · CPC title

• G01C19/5712 Primary

  the devices involving a micromechanical structure · CPC title