Mems sensor with offset anchor load rejection
AssigneeInvenSense, Inc.
InventorsMatthew Thompson, Houri Johari-Galle, Leonardo Baldasarre, Sarah Nitzan, Kirt Williams
Life of this patent
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Abstract
A MEMS sensor includes a MEMS layer, a cap layer, and a substrate layer. The MEMS layer includes a suspended spring-mass system that moves in response to a sensed inertial force. The suspended spring-mass system is suspended from one or more anchors. The anchors are coupled to each of the cap layer and the substrate layer by anchoring components. The anchoring components are offset such that a force applied to the cap layer or the substrate layer causes a rotation of the anchor and such that the suspended spring-mass system substantially remains within the original MEMS layer.
Claims20
A microelectromechanical (MEMS) device, comprising:
- an anchor system bonded to a cap layer and bonded to a substrate layer;
- a proof mass coupled to the anchor system via a spring;
- a sense element coupled between the proof mass and the substrate layer wherein the sense element outputs a signal in response to motion of the proof mass in a first direction;
- wherein a force applied to the anchor system causes the anchor system and the spring to move in the first direction, and
- wherein the proof mass remains substantially stationary when the first force is applied to the anchor system.
A microelectromechanical (MEMS) device, comprising:
- a cap including a first anchoring system;
- a substrate including a second anchoring system, wherein at least one sense electrode is located on a surface of the substrate;
- and
- a MEMS layer bonded to each of the cap and the substrate to define a cavity, wherein the MEMS layer comprises a suspended spring-mass system, wherein the suspended spring-mass system comprises:
- at least one movable mass, wherein at least a portion of the at least one movable mass is located at a first distance from to the at least one sense electrode to form at least one sense capacitor;
- and
- at least one anchoring mass coupled to the at least one movable mass to suspend the at least one movable mass within the MEMS layer, wherein the at least one anchoring mass is coupled to at least a portion of the first anchoring system and at least a portion of the second anchoring system, and wherein in response to a force in a direction perpendicular to the MEMS layer the first anchoring system and the second anchoring system cause the at least one anchoring mass to move in the direction of the force and the at least one movable mass to remains at the first distance from the at least one sense electrode to form the at least one sense capacitor.
A microelectromechanical (MEMS) device, comprising:
- a cap;
- a substrate wherein at least one sense electrode is located on a surface of the substrate;
- a MEMS layer bonded to each of the cap and the substrate to define a cavity, wherein the MEMS layer comprises a suspended spring-mass system;
- at least one post coupled to the cap and one or more anchoring masses of the suspended spring-mass system;
- at least one standoff coupled to the cap and the one or more anchoring masses of the suspended spring mass system,
- wherein the at least one standoff is offset from the at least one post such that the at least one standoff and at least one post do not overlap on opposite faces of the one or more anchoring masses, and
- wherein in response to a force perpendicular to the MEMS layer the one or more anchoring masses move in the direction of the force and at least one proof mass of the spring mass system is substantially stationary.
Dependencies are inferred from the claim text.