Abstract:
A detection, structure (1) for a z-axis resonant accelerometer (24) is provided with an inertial mass (2) anchored to a substrate (20) by means of elastic anchorage elements (6) so as to be suspended above the substrate (20) and perform an inertial movement of rotation about a first axis of rotation (A) belonging to a plane (xy) of main extension of the inertial mass (2), in response to an external acceleration (a-) acting along a vertical axis (z) transverse with respect to the plane (xy); and a first resonator element (10a) and a second resonator element (10b), which are mechanically coupled to the inertial mass (2) by respective elastic supporting elements (16), which enable a movement of rotation about a second axis of rotation (B) and a third axis of rotation (C), in a resonance condition. In particular, the second axis of rotation (B) and the third axis of rotation (C) are parallel to one another, and are moreover parallel to the first axis of rotation (A) of the inertial mass (2).
Abstract:
A MEMS inertial sensor including: a supporting structure; an inertial structure, which includes at least one inertial mass; an elastic structure, which is mechanically coupled to the inertial mass and to the supporting structure so as to enable a movement of the inertial mass in a direction parallel to a first direction, when the supporting structure is subjected to an acceleration parallel to the first direction; and a stopper structure, fixed with respect to the supporting structure and including at least one primary stopper element and one secondary stopper element . If the acceleration exceeds a first threshold value, the inertial mass abuts against the primary stopper element and subsequently rotates about an axis of rotation defined by the primary stopper element. If the acceleration exceeds a second threshold value, rotation of the inertial mass terminates when the inertial mass abuts against the secondary stopper element.
Abstract:
A process for manufacturing a MEMS pressure sensor (42) having a micromechanical structure (35) envisages: providing a wafer (1) having a substrate of semiconductor material and a top surface (2a); forming a buried cavity (10) entirely contained within the substrate (2) and separated from the top surface (2a) by a membrane (12) suspended above the buried cavity (10); forming a fluidic-communication access (22; 37) for fluidic communication of the membrane (12) with an external environment, set at a pressure the value of which has to be determined; forming, suspended above the membrane (12), a plate region (30) made of conductive material, separated from the membrane (12) by an empty space (24); and forming electrical-contact elements (30a, 30b) for electrical connection of the membrane (12) and of the plate region (30), which are designed to form the plates of a sensing capacitor (C), the value of capacitance of which is indicative of the value of pressure to be detected. A corresponding MEMS pressure sensor (42) having the micromechanical structure (35) is moreover described.