Interlocking proof mass for mems inertial sensing device
| DWPI Title: Micro-electro-mechanical system inertial sensing device e.g. accelerometer, for detecting motion of proof masses in directions in airbags of vehicle, has flexures for allowing motion of mass in direction normal to plane of frame and inhibiting motion of mass in direction parallel to plane of frame |
| Abstract: A microelectromechanical systems (MEMS) inertial sensing device having a large proof mass with interlocking tabs is disclosed. The interlocking tabs limit motion of the proof mass when subjected to large inertial forces. The interlocking tabs are formed around the periphery of the proof mass and interact with corresponding interlocking tabs formed in a frame to which the proof mass is tethered. The motion of the proof mass is limited by the interlocking tabs, which are formed during MEMS fabrication of the inertial sensing device rather than as part of the packaging process. With a large proof mass, the inertial sensing device can provide high sensitivity in low inertial force environments while the interlocking tabs protect the device when subjected to high inertial forces. |
| Use: Micro-electro-mechanical system (MEMS) inertial sensing device i.e. accelerometer, for detecting motion of central large proof masses in directions in airbags of a vehicle for high sensitivity applications. |
| Advantage: The device is small in size, so that the device offers lower cost, higher throughput, and higher sensitivity. The device accurately limits motion of large proof masses without relying upon fragile flexures or difficult to control post fabrication processes. The device can provide high sensitivity in low inertial force environments while interlocking tabs protect the device when the device is subjected to high inertial force. |
| Novelty: The device (100) has a central large proof mass (110) including N proof mass interlocking tabs (150) formed around a periphery of the proof mass. A frame (120) includes N frame recesses (155) formed around a periphery of an orifice. Each of the N proof mass interlocking tabs are arranged to fit in a respective one of the N frame recesses. A set of electrostatic pick-offs (140) is formed around the periphery of the orifice. First end of each of a set of flexures (130) is coupled to the proof mass. Second end of each of the set of flexures is coupled to the frame. The set of flexures allows motion of the proof mass in direction normal to a plane of the frame and inhibits the motion of the proof mass in direction parallel to the plane of the frame. |
| Filed: 4/25/2022 |
| Application Number: US17728004A |
| Tech ID: SD 15327.1 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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