Micromechanical component

Abstract

A micromechanical component (1) with a substrate (3) extending along a principal extension plane (100) of the micromechanical component (1), wherein the micromechanical component (1) comprises a first electrode (7) fixed to the substrate (3) via a first suspension (5) and a second electrode (11) fixed to the substrate (3) via a second suspension (9), wherein the first suspension (5) is spaced apart along a first longitudinal axis (101) of the first electrode (7) from a first end face (71) and a second end face (72) of the first electrode (7), wherein the second suspension (9) is spaced apart along a second longitudinal axis (102) of the second electrode (11) from a third end face (111) and a fourth end face (112) of the second electrode (11), characterized in that the first suspension (5) and the second suspension (9) are designed in such a way,that a first projection of the first suspension (5) onto a projection surface extending perpendicular to the principal extension plane (100) and parallel to the first longitudinal axis (101) of the first electrode (7) and a second projection of the second suspension (9) onto the projection surface are disjoint, wherein only a part of a projection of the first suspension (5) onto the principal extension plane (100) comprises a subset of a projection of the first electrode (7) onto the principal extension plane (100).

Description

Prior ArtThe invention is based on a micromechanical component according to the preamble of claim 1.Micromechanical components having a substrate and having electrodes fixed to the substrate via suspensions are generally known.For example, JP 2012-185040 A, US 2011 / 02260 A1, US 2016 / 0047838 A1 and US 2012 / 0262026 A1 disclose micromechanical components of this type.Further micromechanical components are known from publications US 2006 / 0 096 377 A1, DE 10 2013 212 059 A1, DE 10 2012 200 740 A1 and US 2012 / 0 267 150 A1.Disclosure of the InventionIt is an object of the present invention to provide a mechanically robust, simple and cost-effective micromechanical component that is mechanically robust compared to the prior art.The object is achieved in that the first suspension and the second suspension are configured such that a first projection of the first suspension onto a projection surface extending perpendicular to the main extension plane and parallel to the first longitudinal axis of the first electrode and a second projection of the second suspension onto the projection surface are disjunct.This advantageously allows the first electrode and the second electrode not to be connected to the substrate over the full surface and at the same time the first electrode and the second electrode can be connected to conductor tracks which are substantially electrically insulated from one another in a simple manner. In particular, because the first projection and the second projection onto the projection surface are disjunct, conductor tracks can be realized in the micromechanical component in a simple manner substantially perpendicularly to the projection surface. It is thus possible to dispense with additional insulation layers or complicated arrangements of the conductor tracks in the prior art.In addition, by a connection of the first electrode and the second electrode to the substrate which is not over the entire surface, the stress sensitivity of the micromechanical component is reduced in that a deformation of the substrate caused by expansion, for example due to thermal and mechanical loads, deforms the first electrode and the second electrode less strongly in comparison with the prior art or moves them out of an ideal position provided, and the movement detection by the electrodes can therefore be carried out particularly accurately.The present invention thus provides a micromechanical component, deformation of the substrate of the micromechanical component resulting from expansion due to thermal and mechanical loads being less critical. According to the invention, a changing inclination of the fixed electrodes caused by the expansion, which is known from the prior art, is thus avoided or this effect is reduced. A changing parasitic signal in the drive movement is thus reduced or avoided and the stress sensitivity of the micromechanical component becomes less visible to the alignment parameters.A simple and cost-effective micromechanical component that is mechanically robust compared to the prior art is thus provided.The micromechanical component may include a rotation rate sensor. The first electrode and the second electrode are preferably detection electrodes of the micromechanical component. As a result, with the aid of a central suspension of the detection electrodes, the stress sensitivity of rotation rate sensors is reduced in comparison with the prior art. A reduction in the stress sensitivity of rotation rate sensors in offset and quadrature is thus made possible.Advantageous embodiments and developments of the invention can be derived from the dependent claims and from the description with reference to the drawings.According to a preferred development, it is provided that the first suspension is arranged spaced apart from the first end face along the first longitudinal axis by at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, an extent of the first suspension along the first longitudinal axis. This allows a particularly compact and simple suspension of the first electrode and thus a particularly stress-insensitive micromechanical component.According to a preferred development, it is provided that the first suspension is arranged spaced apart from the second end face along the first longitudinal axis by at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, an extent of the first suspension along the first longitudinal axis. This allows a particularly compact and simple suspension of the first electrode and thus a particularly stress-insensitive micromechanical component.According to a preferred development, it is provided that the second suspension is arranged spaced apart from the third end face along the second longitudinal axis by at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, an extent of the second suspension along the second longitudinal axis. This allows a particularly compact and simple suspension of the second electrode and thus a particularly stress-insensitive micromechanical component.According to a preferred development, it is provided that the second suspension is arranged spaced apart from the fourth end face along the second longitudinal axis by at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, an extent of the second suspension along the second longitudinal axis. This allows a particularly compact and simple suspension of the second electrode and thus a particularly stress-insensitive micromechanical component.According to the invention, it is provided that only a part of a projection of the first suspension onto the main extension plane comprises a subset of a projection of the first electrode onto the main extension plane. This allows a targeted formation of the first suspension. This allows a particularly mechanically robust and at the same time compact and simple suspension of the first electrode and thus a particularly stress-insensitive and mechanically robust micromechanical component.According to a preferred development, it is provided that only a part of a projection of the second suspension onto the main extension plane comprises a subset of a projection of the second electrode onto the main extension plane. This allows a particularly mechanically robust and at the same time compact and simple suspension of the second electrode and thus a particularly stress-insensitive and mechanically robust micromechanical component.According to a preferred development, it is provided that the micromechanical component comprises a detection mass that is movable with respect to the substrate, the detection mass enclosing the first electrode and the second electrode at least partially substantially parallel to the main extension plane. This provides a particularly space-saving micromechanical component.According to a preferred development, it is provided that the micromechanical component comprises a third electrode that is movable with respect to the substrate, the detection mass and the third electrode being connected to one another in a rotationally fixed manner. This advantageously allows a force effect acting on the detection mass with the aid of interactions between the first electrode and the third electrode and between the second electrode and the third electrode.According to a preferred development, it is provided that the micromechanical component includes a third suspension for further fixing the first electrode to the substrate and a fourth suspension for further fixing the second electrode to the substrate. This allows a particularly mechanically robust and simultaneously compact and simple suspension of the first electrode and the second electrode and thus a particularly stress-insensitive and mechanically robust micromechanical component.For example, it is also provided that the first suspension and the second suspension are configured such that a first projection of the first suspension onto a projection surface extending perpendicular to the main extension plane and parallel to the first longitudinal axis of the first electrode and a second projection of the second suspension onto the projection surface at least partially overlap. In other words, the first electrode and the second electrode or the fixed electrodes of the micromechanical component are suspended centrally on a line. This allows a particularly central suspension of the first electrode and the second electrode and thus minimizes the influence of substrate distortions on the function of the first electrode and the second electrode.Brief Description of the DrawingsFIGS. 1, 2 and 3 show schematic representations of exemplary embodiments of the present invention.Embodiments of the InventionIn the various figures, identical parts are always provided with the same reference numerals and are therefore generally also designated or mentioned only once in each case.FIGS. 1, 2 and 3 show schematic representations of exemplary embodiments of the present invention.In this case, FIG. 1 shows a micromechanical component 1 having a substrate 3 extending along a main extension plane 100 of micromechanical component 1, micromechanical component 1 including a first electrode 7 fixed to substrate 3 via a first suspension 5, and a second electrode 11 fixed to substrate 3 via a second suspension 9. According to the invention, the first suspension 5 is arranged spaced apart along a first longitudinal axis 101 of the first electrode 7 from a first end face 71 and a second end face 72 of the first electrode 7. Furthermore, according to the invention, the second suspension 9 is arranged spaced apart along a second longitudinal axis 102 of the second electrode 11 from a third end face 111 and a fourth end face 112 of the second electrode 11. Furthermore, it is provided according to the invention that the first suspension 5 and the second suspension 9 are configured such that a first projection of the first suspension 5 onto a projection surface extending perpendicular to the main extension plane 100 and parallel to the first longitudinal axis 101 of the first electrode 7 and a second projection of the second suspension 9 onto the projection surface are disjunct. In other words, the first suspension 5 and the second suspension 9 or the electrode suspensions are suspended slightly offset above and below a line. A concept with differential evaluation is thus made possible in a particularly simple manner.In FIG. 1, it is exemplarily shown that the first suspension 5 along the first longitudinal axis 101 is arranged at a distance of at least four times an extension of the first suspension 5 along the first longitudinal axis 101 from the first end face 71. Alternatively, it is also provided, for example, that the first suspension 5 is arranged spaced apart from the first end face 71 along the first longitudinal axis 101 by at least one, preferably at least twice, particularly preferably at least three times, an extension of the first suspension 5 along the first longitudinal axis 101.Furthermore, FIG. 1 shows by way of example that the first suspension 5 is arranged spaced apart from the second end face 72 along the first longitudinal axis 101 by at least five times an extent of the first suspension 5 along the first longitudinal axis 101. Alternatively, however, it is also provided, for example, that the first suspension 5 along the first longitudinal axis 101 is arranged at least once, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, an extension of the first suspension 5 along the first longitudinal axis 101 at a distance from the second end face 72.In addition, in micromechanical component 1 shown by way of example in FIG. 1, second suspension 9 is situated at a distance from third end face 111 along second longitudinal axis 102 of at least five times an extent of second suspension 9 along second longitudinal axis 102. For example, it is alternatively also provided that the second suspension 9 is arranged spaced apart from the third end face 111 along the second longitudinal axis 102 by at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, an extension of the second suspension 9 along the second longitudinal axis 102.Furthermore, FIG. 1 shows that the second suspension 9 along the second longitudinal axis 102 is arranged at a distance of at least four times an extent of the second suspension 9 along the second longitudinal axis 102 from the fourth end face 112. Alternatively, it is also provided, for example, that the second suspension 9 along the second longitudinal axis 102 is arranged at least once, preferably at least twice, particularly preferably at least three times, an extension of the second suspension 9 along the second longitudinal axis 102 at a distance from the fourth end face 112.Due to the simple, central suspension of the first electrode 7 and the second electrode 9 or the detection electrodes, it is advantageously possible that the effect of the substrate distortion on the movement detection of the electrodes is reduced.Furthermore, FIGS. 1 and 2 show by way of example that only a part of a projection of the first suspension 5 onto the main extension plane 100 comprises a subset of a projection of the first electrode 7 onto the main extension plane 100. In addition, FIGS. 1 and 2 show that only a part of a projection of the second suspension 9 onto the main extension plane 100 comprises a subset of a projection of the second electrode 11 onto the main extension plane 100.FIG. 2 shows by way of example that micromechanical component 1 includes a third suspension 17 for further fixing first electrode 7 to substrate 3 and a fourth suspension 19 for further fixing second electrode 11 to substrate 3. In this case, the third suspension 17 and the fourth suspension 19 are formed and arranged substantially in the same way as the first suspension 5 and the second suspension 9.In the exemplary embodiment illustrated in FIG. 2, the first suspension 5 along the first longitudinal axis 101 is arranged at a distance from the first end face 71 less than the simple expansion of the first suspension 5 along the first longitudinal axis 101. Furthermore, the first suspension 5 along the first longitudinal axis 101 is arranged at a distance of at least nine times the extent of the first suspension 5 along the first longitudinal axis 101 from the second end face 72.Furthermore, the third suspension 17 is arranged spaced apart from the first end face 71 along the first longitudinal axis 101 at least eight times an extent of the third suspension 5 along the first longitudinal axis 101. Furthermore, the third suspension 17 along the first longitudinal axis 101 is arranged at least once, and preferably less than twice, the extent of the third suspension 17 along the first longitudinal axis 101 at a distance from the second end face 72.Furthermore, FIG. 2 shows by way of example that the second suspension 9 along the second longitudinal axis 102 is arranged at a distance of at least one, and preferably less than twice, an extent of the second suspension 9 along the second longitudinal axis 102 from the third end face 111. Furthermore, the second suspension 9 along the second longitudinal axis 102 is arranged at a distance of at least eight times an extent of the second suspension 9 along the second longitudinal axis 102 from the fourth end face 112.Furthermore, the fourth suspension 19 along the second longitudinal axis 102 is arranged at a distance of at least nine times an extent of the fourth suspension 19 along the second longitudinal axis 102 from the third end face 111. Furthermore, the fourth suspension 19 along the second longitudinal axis 102 is arranged at a distance from the fourth end face 112 less than the simple of an expansion of the fourth suspension 19 along the second longitudinal axis 102.Thus, a selective arrangement and configuration of the first suspension 5, the second suspension 9, the third suspension 17 and the fourth suspension 19 enables capacitive detection of detection movement in rotation rate sensors by electrodes suspended several times and at the same time the first electrode and the second electrode are connected in a simple manner to conductor tracks which are essentially electrically insulated from one another. In this way, micromechanical component 1 may be adjusted in a targeted manner by weighing between increased stress sensitivity and increased mechanical stability of the first and second electrodes by multiple suspension.FIG. 3 shows, by way of example, that micromechanical component 1 includes a detection mass 13 that is movable relative to substrate 3. Here, the detection mass 13 encloses the first electrode 7 and the second electrode 11 at least partially substantially parallel to the main extension plane 100.Furthermore, FIGS. 1, 2 and 3 show that micromechanical component 1 includes a third electrode 15 that is movable relative to substrate 3, detection mass 13 and third electrode 15 being connected to one another in a rotationally fixed manner.Micromechanical component 1 shown by way of example in FIG. 3 includes a multiplicity of first suspensions 5, fixed first electrodes 7, second suspensions 9, fixed second electrodes 11 and third electrodes 15.Moreover, micromechanical component 1 shown by way of example in FIG. 3 includes a first spring 21 and a second spring 23, first spring 21 and second spring 23 being designed and anchored or suspended on substrate 3 and on detection mass 13 in such a way that detection mass 13 and third electrode 15 are deflectable substantially parallel to main plane of extension 100 and perpendicular to first longitudinal axis 101. This advantageously allows a force effect acting on the detection mass 13 to be measured on the basis of changes in distance between the first electrode 7 and the third electrode 15 or between the second electrode 11 and the third electrode 15. Alternatively, it is also provided, for example, that the first spring 21 and the second spring 23 are designed and anchored or suspended on the substrate 3 and on the detection mass 13 such that the detection mass 13 and the third electrode 15 can be deflected substantially parallel to the main extension plane 100 and parallel to the first longitudinal axis 101. In this way, it is advantageously possible that a force effect acting on the detection mass 13 can be measured on the basis of changes in an overlap of projections of the first electrode 7 and the third electrode 15 or of the second electrode 11 and the third electrode 15 substantially parallel to the main extension plane and perpendicular to the first longitudinal axis 101.

Claims

Micromechanical component (1) having a substrate (3) extending along a main plane of extension (100) of the micromechanical component (1), the micromechanical component (1) comprising a first electrode (7) fixed to the substrate (3) via a first suspension (5) and a second electrode (11) fixed to the substrate (3) via a second suspension (9), the first suspension (5) being arranged spaced apart from a first end face (71) and a second end face (72) of the first electrode (7) along a first longitudinal axis (101) of the first electrode (7), the second suspension (9) being arranged spaced apart from a third end face (111) and a fourth end face (112) of the second electrode (11) along a second longitudinal axis (102) of the second electrode (11), characterized in that the first suspension (5) and the second suspension (9) are designed in such a way, a first projection of the first suspension (5) onto a projection surface extending perpendicular to the main extension plane (100) and parallel to the first longitudinal axis (101) of the first electrode (7) and a second projection of the second suspension (9) onto the projection surface are disjunct, wherein only a part of a projection of the first suspension (5) onto the main extension plane (100) comprises a subset of a projection of the first electrode (7) onto the main extension plane (100).Micromechanical component (1) according to Claim 1, wherein the first suspension (5) is arranged at a distance from the first end face (71) along the first longitudinal axis (101) of at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, of an extent of the first suspension (5) along the first longitudinal axis (101).Micromechanical component (1) according to one of the preceding claims, wherein the first suspension (5) is arranged at a distance from the second end face (72) along the first longitudinal axis (101) of at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, of an extent of the first suspension (5) along the first longitudinal axis (101).Micromechanical component (1) according to one of the preceding claims, wherein the second suspension (9) is arranged at a distance from the third end face (111) along the second longitudinal axis (102) of at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, of an extent of the second suspension (9) along the second longitudinal axis (102).Micromechanical component (1) according to one of the preceding claims, wherein the second suspension (9) is arranged at a distance from the fourth end face (112) along the second longitudinal axis (102) of at least one, preferably at least twice, particularly preferably at least three times, very particularly preferably at least four times, of an extent of the second suspension (9) along the second longitudinal axis (102).Micromechanical component (1) according to one of the preceding claims, wherein only a part of a projection of the second suspension (9) onto the main extension plane (100) comprises a subset of a projection of the second electrode (11) onto the main extension plane (100).Micromechanical component (1) according to one of the preceding claims, wherein the micromechanical component (1) comprises a detection mass (13) which is movable with respect to the substrate (3), wherein the detection mass (13) encloses the first electrode (7) and the second electrode (11) at least partially substantially parallel to the main plane of extent.Micromechanical component (1) according to one of the preceding claims, the micromechanical component (1) comprising a third electrode (15) which is movable with respect to the substrate (3), the detection mass (13) and the third electrode (15) being connected to one another in a rotationally fixed manner.Micromechanical component (1) according to one of the preceding claims, wherein the micromechanical component (1) comprises a third suspension (17) for further fixing the first electrode (7) to the substrate (3) and a fourth suspension (19) for further fixing the second electrode (11) to the substrate (3).

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