Abstract
A micromechanical spring structure, including a spring beam and a rigid micromechanical structure, the spring beam including a first end and an opposing second end along a main extension direction. The spring beam includes a fork having two support arms on at least one of the two ends, which is anchored to the rigid micromechanical structure, the two support arms being anchored to a surface of the rigid micromechanical structure, which extends perpendicular to the main extension direction of the spring beam.
Claims
1-5. (canceled)
6. A micromechanical spring structure, comprising: a spring beam; and a rigid micromechanical structure; wherein the spring beam includes a first end and an opposing second end along a main extension direction, wherein the spring beam includes a fork having two support arms on at least one of the two ends, which is anchored to the rigid micromechanical structure, and wherein the two support arms are anchored to a surface of the rigid micromechanical structure, which extends perpendicular to the main extension direction of the spring beam.
7. The micromechanical spring structure of claim 6, wherein the rigid micromechanical structure includes a substrate anchor.
8. The micromechanical spring structure of claim 6, wherein the rigid micromechanical structure includes a movable structure.
9. The micromechanical spring structure of claim 6, wherein the fork forms a rectangular frame.
10. The micromechanical spring structure of claim 6, wherein the fork forms a semicircular frame or an elliptical frame.
11. The micromechanical spring structure of claim 7, wherein the fork forms a semicircular frame or an elliptical frame.
12. The micromechanical spring structure of claim 8, wherein the fork forms a semicircular frame or an elliptical frame.
13. The micromechanical spring structure of claim 7, wherein the fork forms a rectangular frame.
14. The micromechanical spring structure of claim 8, wherein the fork forms a rectangular frame.
15. The micromechanical spring structure of claim 6, wherein the rigid micromechanical structure includes a movable structure, which includes a seismic mass.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 shows a first micromechanical spring structure, including a spring beam and a rigid micromechanical structure in the related art.
[0007] FIG. 2 shows a micromechanical spring structure according to the present invention, including a spring beam and a rigid micromechanical structure in a first exemplary embodiment.
[0008] FIG. 3 shows a micromechanical spring structure according to the present invention, including a spring beam and a rigid micromechanical structure in a second exemplary embodiment.
[0009] FIG. 4 shows a second micromechanical spring structure, including a spring beam and a rigid micromechanical structure in the related art.
[0010] FIG. 5 shows a micromechanical spring structure according to the present invention, including a spring beam and a rigid micromechanical structure in a third exemplary embodiment.
DETAILED DESCRIPTION
[0011] FIG. 1 shows a first micromechanical spring structure, including a spring beam and a rigid micromechanical structure in the related art. Spring beam 100 includes a first end 120 and an opposing second end 130 along a main extension direction 110. First end 120 of spring beam 100 is anchored to a surface 210 of rigid micromechanical structure 200. Surface 210 extends perpendicular to main extension direction 110 of the spring beam. Second end 130 of spring beam 100 is deflectable in a direction 300, which extends in parallel to surface 210. Spring beam 100 bends as a result. The device shown is a micromechanical structure above the surface of a substrate. Rigid micromechanical structure 200 is configured as a substrate anchor and essentially does not deform.
[0012] FIG. 2 shows a micromechanical spring structure according to the present invention, including a spring beam and a rigid micromechanical structure in a first exemplary embodiment. Unlike the spring structure in the related art shown in FIG. 1, first end 120 of spring beam 100 includes a fork 140 having two support arms 141, 142, which are anchored to rigid micromechanical structure 200. In this configuration, two support arms 141, 142 are anchored to surface 210 of rigid micromechanical structure 200, which extends perpendicular to main extension direction 110 of spring beam 100.
[0013] Rigid micromechanical structure 200 may be a substrate anchor. Rigid micromechanical structure 200 may also be a moveable structure, in particular, a seismic mass. A fork 140 may be situated not only on the first end, but additionally or alternatively also on the second end of the spring beam.
[0014] The fork according to FIG. 2 forms a frame or a frame structure. The frame structure is inserted in a micromechanical sensor between the substrate anchor and the spring structure or also between the spring structure and the mass structure. In the example of FIG. 2, the frame structure is introduced between the substrate anchor and the spring structure. The fork 140 forms a rectangular frame. The side lengths and widths of the frame are to be appropriately adjusted in order to optimally reduce the non-linearity. Lateral tensile forces are compensated for by the bending of the frame. The bend is small in proportion to the deflection of the spring structure. The frame structure may be dimensioned in such a way that a corresponding degree of non-linearity is reduced. With a frame size of 1020 m.sup.2, for example, the non-linearity is reduced by more than 50% in a beam 800 m in length clamped on both sides. This involves simulation results. The first normal mode of the frame is at 100 times the fundamental oscillation.
[0015] FIG. 3 shows a micromechanical spring structure according to the present invention, including a spring beam and a rigid micromechanical structure in a second exemplary embodiment. Alternatively to the first exemplary embodiment, fork 140 forms a semicircular frame or an elliptical frame.
[0016] FIG. 4 shows a second micromechanical spring structure, including a spring beam and a rigid micromechanical structure in the related art. Spring beam 100 includes a first end 120 and an opposing second end 130 along a main extension direction 110. First end 120 of spring beam 100 is anchored to a surface 210 of rigid micromechanical structure 200, which is configured as a moveable structure. Surface 210 extends perpendicular to main extension direction 110 of the spring beam. First end 120 of spring beam 100, together with rigid micromechanical structure 200, is deflectable in a direction 300, which extends in parallel to surface 210. Spring beam 100 bends as a result. Rigid micromechanical structure 200 is configured as a seismic mass and essentially does not deform. Second end 130 of spring beam 100 is connected to a suspension beam 400. Suspension beam 400 essentially does not deform. Suspension beam 400, in turn, is connected to an end of an additional spring beam 410. Another opposing end of additional spring beam 410 is connected to a substrate anchor 420. Additional spring beam 410 extends in parallel to spring beam 100. A mirror image of this structure is repeated on the plotted symmetry axis (dotted-dashed line) in parallel to main extension direction 110 of spring beam 100. The structure is referred to below as a double-folded beam structure DFBS.
[0017] FIG. 5 shows a micromechanical spring structure according to the present invention, including a spring beam and a rigid micromechanical structure in a third exemplary embodiment. Unlike the spring structure in the related art shown in FIG. 1, first end 120 of spring beam 100 includes a fork 140 having two support arms 141, 142, which is anchored to rigid micromechanical structure 200. In this configuration, two support arms 141, 142 are anchored to surface 210 of rigid micromechanical structure 200, which extends perpendicular to main extension direction 110 of spring beam 100.
[0018] Fork 140 according to FIG. 5 forms a frame or a frame structure. The frame structure is situated between the mass element and the spring structure. A dimension of the DFBS of 180150 m and a frame size of 1020 m.sup.2 result in a reduction of the non-linearity of 30%. This involves simulation results.
[0019] The frame in the present exemplary embodiment is filled out by rigid micromechanical structure 200 at a certain distance from support arms 141, 142, or the frame is countersunk in recesses in rigid micromechanical structure 200. This serves the purpose of optimally utilizing the present installation space by increasing the extension and, therefore, the mass of fixed rigid micromechanical structure 200 without adversely affecting the function of fork 140 in the process.
[0020] The List of Reference Numerals is as follows:
TABLE-US-00001 100 spring beam 110 main extension direction 120 first end 130 second end 140 fork 141 first support arm 142 second support arm 200 rigid micromechanical structure 210 surface of the rigid micromechanical structure 300 direction of a deflection 400 suspension beam 410 additional spring beam 420 substrate anchor
