Inertial sensor
A micro vibration body includes a curved surface portion, a recessed portion recessed from the curved surface portion, a bottom surface protruding portion protruding from a bottom surface of the recessed portion, and a through hole in the bottom surface protruding portion. A mounting substrate has a positioning recess, into which the bottom surface protruding portion is inserted, and electrode portions surrounding the inner frame portion. A joining member is in the positioning recess and joins the bottom surface protruding portion with the mounting substrate. The bottom surface is in contact with a region of the mounting substrate around the positioning recess. The bottom surface protruding portion has a tip end surface that is at a distance from the positioning recess. The joining member at least partially enters the through hole and is electrically connected to the conductive layer.
1. An inertial sensor comprising:
a micro vibration body that is a walled member having a front surface, which is a surface on a side having an outer diameter, and a back surface, which is an opposite surface to the front surface, the micro vibration body including a curved surface portion, which has an annular curved surface, a recessed portion, which is recessed from the curved surface portion to a center of the micro vibration body, a bottom surface protruding portion, which protrudes from a bottom surface of the recessed portion on a side of the back surface, a through hole, which is in the bottom surface protruding portion and communicates the front surface with the back surface, and a conductive layer, which covers at least a part of the front surface;
a mounting substrate that includes a lower substrate and an upper substrate, which are joined to each other, the lower substrate having a positioning recess into which the bottom surface protruding portion of the micro vibration body is inserted, the upper substrate including an inner frame portion, which surrounds a periphery of the positioning recess, and a plurality of electrode portions, which are separated from each other and surround the inner frame portion; and
a joining member that is provided in the positioning recess and joins the bottom surface protruding portion of the micro vibration body with the mounting substrate, wherein
the curved surface portion of the micro vibration body is hollow,
the bottom surface is in contact with a region of the mounting substrate around the positioning recess,
a tip end of the bottom surface protruding portion has a tip end surface distal to the bottom surface,
the positioning recess is spaced apart from the tip end surface, and
the joining member at least partially enters the through hole and is electrically connected to the conductive layer.
2. The inertial sensor according to claim 1 , wherein
the conductive layer covers at least a part of an inner wall of the through hole,
the inner wall of the through hole includes an upper end at the front surface and a lower end at the back surface, and
the conductive layer extends, such that at least a part of the conductive layer connects the upper end of the inner wall of the through hole with the lower end of the inner wall of the through hole.
3. The inertial sensor according to claim 1 , wherein
the conductive layer covers at least the front surface of a rim of the micro vibration body, which faces the plurality of the electrode portions, and
the conductive layer covers only a side of the front surface.
4. The inertial sensor according to claim 1 , wherein
the joining member fills a part of the positioning recess.
5. The inertial sensor according to claim 1 , wherein
the bottom surface protruding portion has a tapered shape or a curved shape, such that an outer diameter of a tip end of the bottom surface protruding portion is smaller than an outer diameter of a bottom end of the bottom surface protruding portion.