Inertial sensor, electronic apparatus, and vehicle
View Patent ↗An inertial sensor includes: a substrate; a moving element swinging about a swing axis along a Y-axis; a detection electrode provided at the substrate, overlapping the moving element as viewed in a plan view from a Z-axis direction orthogonal to the Y-axis, and forming an electrostatic capacitance with the moving element; an exposure part provided at an inner side of the detection electrode and exposing a surface facing the moving element, of the substrate; a protrusion overlapping the moving element as viewed in a plan view from the Z-axis direction and protruding toward the moving element from the exposure part of the substrate; and a covered electrode provided at a top of the protrusion and having a same electric potential as the moving element.
1. An inertial sensor comprising:
a substrate;
a moving element swinging about a swing axis along a Y-axis;
a detection electrode provided at the substrate, overlapping the moving element as viewed in a plan view from a Z-axis direction orthogonal to the Y-axis, and forming an electrostatic capacitance with the moving element;
an exposure part provided at an inner side of the detection electrode as viewed in a plan view from the Z-axis direction and exposing a surface facing the moving element, of the substrate;
a protrusion overlapping the moving element as viewed in a plan view from the Z-axis direction and protruding toward the moving element from the exposure part of the substrate;
a covered electrode provided at a top of the protrusion and having a same electric potential as the moving element;
a dummy electrode provided at the substrate, overlapping an area of the moving element not overlapping the detection electrode as viewed in a plan view from the Z-axis direction, and having a same electric potential as the moving element; and
a coupling wiring provided at the exposure part and coupling the dummy electrode and the covered electrode together.
2. The inertial sensor according to claim 1 , wherein
the exposure part is open to an outer edge of the detection electrode.
3. The inertial sensor according to claim 2 , wherein
the detection electrode is provided between the dummy electrode and the swing axis as viewed in a plan view from the Z-axis direction, and
the exposure part is open to the outer edge at the dummy electrode side of the detection electrode.
4. The inertial sensor according to claim 2 , wherein
the dummy electrode is provided between the detection electrode and the swing axis as viewed in a plan view from the Z-axis direction, and
the exposure part is open to the outer edge at the dummy electrode side of the detection electrode.
5. The inertial sensor according to claim 2 , wherein
the exposure part is open to the outer edge at one side of the Y-axis direction of the detection electrode.
6. An inertial sensor comprising:
a substrate;
a moving element swinging about a swing axis along a Y-axis;
a detection electrode provided at the substrate, overlapping the moving element as viewed in a plan view from a Z-axis direction orthogonal to the Y-axis, and forming an electrostatic capacitance with the moving element;
an exposure part provided at an inner side of the detection electrode as viewed in a plan view from the Z-axis direction and exposing a surface facing the moving element, of the substrate;
a protrusion overlapping the moving element as viewed in a plan view from the Z-axis direction and protruding toward the moving element from the exposure part of the substrate;
a covered electrode provided at a top of the protrusion and having a same electric potential as the moving element; and
a dummy electrode provided at the substrate, overlapping an area of the moving element not overlapping the detection electrode as viewed in a plan view from the Z-axis direction, and having a same electric potential as the moving element,
wherein the exposure part has a closed shape that is not open to the outer edge of the detection electrode, and
the inertial sensor further comprises a coupling wiring provided inside the substrate and coupling the dummy electrode and the covered electrode together.
7. An inertial sensor comprising:
a substrate;
a moving element swinging about a swing axis along a Y-axis;
a detection electrode provided at the substrate, overlapping the moving element as viewed in a plan view from a Z-axis direction orthogonal to the Y-axis, and forming an electrostatic capacitance with the moving element;
an exposure part provided at an inner side of the detection electrode as viewed in a plan view from the Z-axis direction and exposing a surface facing the moving element, of the substrate;
a covered electrode provided at the exposure part and having a same electric potential as the moving element;
a protrusion overlapping the covered electrode as viewed in a plan view from the Z-axis direction and protruding toward the covered electrode from the moving element;
a dummy electrode provided at the substrate, overlapping an area of the moving element not overlapping the detection electrode as viewed in a plan view from the Z-axis direction, and having a same electric potential as the moving element; and
a coupling wiring provided at the exposure part and coupling the dummy electrode and the covered electrode together.
8. An electronic apparatus comprising:
the inertial sensor according to claim 1 ; and
a control circuit performing control based on a detection signal outputted from the inertial sensor.
9. A vehicle comprising:
the inertial sensor according to claim 1 ; and
a control circuit performing control based on a detection signal outputted from the inertial sensor.