Common mode rejection structures for mems devices
AssigneeNXP USA, Inc.
InventorsMostafa Soliman, Aaron A. Geisberger
Life of this patent
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Abstract
A MEMS device and method of forming the same includes paired masses suspended above a substrate includes linkages that couple pairs of masses to each other. Inner sense linkages couple interior edges of adjacent masses to each other. The inner sense linkages are configured to exhibit a first stiffness when the adjacent masses coupled to each inner sense linkage move out-of-phase relative to each other along a preferred axis of the inner sense linkages and to exhibit a second, increased stiffness in response to in-phase motion of the adjacent masses coupled to each inner sense linkage.
Claims18
A microelectromechanical system (MEMS) device comprising:
- a substrate;
- first, second, third, and fourth masses suspended above the substrate, wherein:
- the first mass is directly adjacent to the second mass and the third mass;
- the second mass is directly adjacent to the first mass and the fourth mass;
- and
- the third mass is directly adjacent to the first mass and the fourth mass;
- a first inner sense linkage that is disposed between the first mass and the third mass and coupled to the first mass and the third mass;
- and
- a second inner sense linkage that is disposed between the second mass and the fourth mass and coupled to the second mass and the fourth mass;
- wherein each inner sense linkage comprises:
- an upper portion;
- a lower portion;
- a central torsion flexure having a first end coupled to the upper portion of the inner sense linkage and second end coupled to the lower portion of the inner sense linkage;
- and
- a first torsion spring coupled between the upper portion of the inner sense linkage and the lower portion of the inner sense linkage;
- and having a middle portion coupled to the central torsion flexure at a location between the first end of the central torsion flexure and the second end of the central torsion flexure;
- and
- wherein, when the upper and lower portions of the inner sense linkage move in phase with each other along an axis parallel to the central torsion flexure and the upper and lower portions of the inner sense linkage are displaced by a predetermined distance, the first torsion spring is configured to exhibit an increase in stiffness.
A method comprising:
- forming first, second, third, and fourth masses suspended above a substrate, wherein:
- the first mass is directly adjacent to the second mass and the third mass;
- the second mass is directly adjacent to the first mass and the fourth mass;
- and
- the third mass is directly adjacent to the first mass and the fourth mass;
- forming a first inner sense linkage that is disposed between the first mass and the third mass and coupled to the first mass and the third mass;
- and
- forming a second inner sense linkage that is disposed between the second mass and the fourth mass and coupled to the second mass and the fourth mass;
- wherein each inner sense linkage comprises:
- an upper portion;
- a lower portion;
- a central torsion flexure having a first end coupled to the upper portion of the inner sense linkage and second end coupled to the lower portion of the inner sense linkage;
- and
- a first torsion spring coupled between the upper portion of the inner sense linkage and the lower portion of the inner sense linkage;
- and having a middle portion coupled to the central torsion flexure at a location between the first end of the central torsion flexure and the second end of the central torsion flexure;
- and
- wherein, when the upper and lower portions of the inner sense linkage move in phase with each other along an axis parallel to the central torsion flexure and the upper and lower portions of the inner sense linkage are displaced by a predetermined distance, the first torsion spring is configured to exhibit an increase in stiffness.
Dependencies are inferred from the claim text.