Micromechanical sensor with multiple spring bars
View Patent ↗A micromechanical sensor comprising a substrate ( 5 ) and at least one mass ( 6 ) which is situated on the substrate ( 5 ) and which moves relative to the substrate ( 5 ) is used to detect motions of the sensor based on an acceleration force and/or Coriolis force which occur(s). The mass ( 6 ) and the substrate ( 5 ) and/or two masses which move toward one another are connected by at least one bending spring device ( 1 ) for a relative rotational motion. The bending spring device ( 1 ) has multiple, in particular two, spring bars ( 2 ) extending essentially parallel to one another for improving the linear spring characteristic of the bending spring device during the rotational motion, and at least one meander ( 3 ) on at least one, preferably on all, of the spring bars ( 2 ).
1. A micromechanical sensor, comprising:
a substrate;
an anchor coupled to the substrate;
a bending spring device responsive to a rotational movement about the anchor, the bending spring device comprising spring bars that extend substantially parallel from the anchor to one or more masses, wherein each spring bar comprises:
a first end being coupled to the anchor; and
a second end being coupled to the one or more masses; and
a meander located between the first and the second end, wherein a total length of at least one spring bar is greater than a length of bars of the meander so as to improve a linear spring characteristic of the bending spring device.
2. The micromechanical sensor according to claim 1 , wherein the meander merges into at least one of the spring bars in a rounded manner.
3. The micromechanical sensor according to claim 1 , wherein one of the spring bars merges in a rounded manner into at least one of the masses, the substrate, and the anchor for attachment to the substrate.
4. The micromechanical sensor according to claim 3 , wherein a rounded transition associated with the rounded manner has a non-constant radius of curvature.
5. The micromechanical sensor according to claim 3 , wherein a rounded transition associated with the rounded manner is elliptical.
6. The micromechanical sensor according to claim 1 , wherein one of the spring bars merges in a branched manner into at least one of the masses, the substrate, and the anchor for attachment to the substrate.
7. The micromechanical sensor according to claim 1 , wherein at least one of the meander and the spring bars has an elliptical bend.
8. The micromechanical sensor according to claim 1 , wherein the meander is placed off-center with respect to the at least one of the spring bars, and is closer to moving components than to a stationary anchoring of the at least one bending spring.
9. The micromechanical sensor according to claim 1 , wherein a distance between bars of the meander is less than a distance between two spring bars.
10. The micromechanical sensor according to claim 1 , wherein a distance between two of the spring bars is a multiple of a width of the spring bars.
11. The micromechanical sensor according to claim 1 , wherein the bending spring device is deflected about the anchoring point in a substantially linear deflection path in response to a torque acting on the one or more masses, the bending spring device having a substantially constant spring characteristic curve.
12. The micromechanical sensor according to claim 1 , wherein both a double spring bar included in the spring bars and the meander have a symmetrical design.
13. The micromechanical sensor according to claim 1 , wherein the meander has a radius of curvature associated with an internal center of curvature inside the meander.
14. The micromechanical sensor according to claim 1 , wherein the meander has at least one further radius of curvature associated with a center of curvature outside the meander.
15. The micromechanical sensor according to claim 1 , wherein the bending spring device is coupled to both a sensor mass and a drive mass.
16. The micromechanical sensor according to claim 1 , wherein the meander is located off-center with respect to the spring bar.
17. The micromechanical sensor according to claim 1 , wherein the spring bars are substantially parallel to each other.
18. The micromechanical sensor according to claim 1 , wherein the spring bars are tapered toward each other.
19. The micromechanical sensor according to claim 1 , wherein the bars of the meander have a different length than bars of another meander.
20. The micromechanical sensor according to claim 1 , wherein the bending spring device inhibits an out-of-plane motion.