Mems device mechanism enhancement for robust operation through severe shock and acceleration

Abstract

A micro-electro-mechanical systems (MEMS) device comprises at least one proof mass configured to have a first voltage and a motor motion in a first horizontal direction. At least one sense plate is separated from the proof mass by a sense gap, with the sense plate having an inner surface facing the proof mass and a second voltage different than the first voltage. A set of stop structures are on the inner surface of the sense plate and are electrically isolated from the sense plate. The stop structures are configured to prevent contact of the inner surface of the sense plate with the proof mass in a vertical direction. The stop structures have substantially the same voltage as that of the proof mass, and are dimensioned to minimize energy exchange upon contact with the proof mass during a shock or acceleration event.

Description

Background technique [0001] Microelectromechanical systems (MEMS) devices may include various sensors, such as gyroscopes and accelerometers, which may be implemented in various control systems and inertial navigation applications, such as inertial measurement units (IMUs). A MEMS gyroscope or accelerometer may include a microstructured sensing element, such as a proof mass, interposed between a pair of sensing plates to form a capacitive sensor. [0002] Operation of MEMS sensors may be disturbed or prevented when subjected to very high levels of shock or vibration. One identified cause of this operational failure is contact between the proof mass and one or both of the sense plates that the proof mass oscillates. When contact of the proof mass to the sensor plate occurs, an exchange of charge occurs and may result in disturbance or loss of the sensor signal. [0003] Currently, MEMS sensors rely primarily on proof-mass support springs that have stiffness in a direction per...

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