Sensor arrangement

Abstract

Sensor arrangement (1) comprising a substrate (2) having a principal extension plane (100), a seismic mass (3) and at least one at least partially cantilevered electrode (4), wherein the seismic mass (3) is movably attached to the substrate (2) in a suspension area (5) about a torsion axis (6) parallel to the principal extension plane (100) and wherein the seismic mass (3) has an asymmetric mass distribution with respect to the torsion axis (6) and the electrode (4) is connected to the substrate (2) in a connection area (7), wherein a surface of the seismic mass (3) facing the substrate (2) is symmetrical with respect to the torsion axis (6) and the connection area (7) is arranged perpendicular to the torsion axis (6) and parallel to the principal extension plane (100) in the area of ​​the suspension area (5) or immediately adjacent to the suspension area (5).

Description

State of the art

[0001] The invention is based on a sensor arrangement with a substrate having a principal extension plane and a seismic mass, wherein the seismic mass is movable about a torsion axis parallel to the principal extension plane and wherein the seismic mass has a mass distribution asymmetric with respect to the torsion axis.

[0002] Such sensor arrangements are generally known. For example, a sensor is known from publication EP 0 244 581 A1 which has a silicon plate in which two identical pendulums with asymmetrically designed rotating masses are formed by etching technique and wherein the masses of the pendulums are each attached to a torsion bar. Further disclosures are found in the publications US 2007 / 0 000 323 A1, US 5 249 465 A, DE 10 2008 042 357 A1, US 5 591 910 A, DE 10 2008 043 524 A1.

[0003] Furthermore, a micromechanical accelerometer is known from EP 0 773 443 A1, wherein at least one first electrode for forming a variable capacitance is provided on a first semiconductor wafer, and wherein a movable electrode in the form of an asymmetrically suspended rocker is provided on a second semiconductor wafer. Due to the asymmetric suspension, when the micromechanical accelerometer is accelerated perpendicular to the wafer surface of the first semiconductor wafer, the rocker experiences a torque about an axis of rotation of the first electrode, wherein a deflection of the rocker as a result of this torque can be detected by a change in the electrical capacitance between the first and the second electrode. The change in capacitance is thus a measure of the acting acceleration.

[0004] A disadvantage of this accelerometer is that, due to the asymmetric mass distribution of the first electrode, its underside does not have a symmetrical geometry relative to the top side of the substrate with respect to the axis of rotation. This means that when potential differences occur between the first electrode and the substrate, for example, due to trapped surface charges on the silicon surfaces, an effective force is generated on the first electrode, since in this case, the surface charges are also not symmetrically distributed with respect to the axis of rotation due to the asymmetric geometry of the first electrode. In particular, if these surface potentials change depending on the temperature or the sensor's lifetime, there is a risk of tipping due to the effective forces, leading to undesirable offset signals and a reduction in the sensor's measurement accuracy.

[0005] Another disadvantage of the accelerometer is that if the substrate bends due to external stress, for example caused by mechanical stresses of an outer housing or thermomechanical stresses in the substrate, the distances between the first and second electrodes change, which also generates unwanted offset signals and a reduction in the measurement accuracy of the sensor. Disclosure of the invention

[0006] The sensor arrangement according to the main claim has the advantage over the prior art that, on the one hand, the measurement accuracy is increased in a comparatively simple and cost-effective manner, and on the other hand, the risk of unwanted offset signals is reduced. In particular, the sensitivity of the sensor arrangement to surface charges and / or to mechanical stress is reduced. A reduction in the sensitivity of the sensor arrangement to surface charges is achieved by making the surface of the seismic mass facing the substrate symmetrical with respect to the axis of torsion, so that the forces exerted by potential differences between the side of the seismic mass facing the substrate and the substrate on both sides of the axis of torsion essentially cancel each other out.Advantageously, the resulting force on the seismic mass is essentially zero, so that even changes in surface potential due to temperature and / or lifetime do not cause any unwanted deflection of the seismic mass. The sensitivity of the sensor assembly to mechanical stress is reduced by arranging the connection area perpendicular to the axis of torsion and parallel to the main plane of extension within the suspension area and / or immediately adjacent to it. This means that if the substrate bends, the geometry between the electrode and the seismic mass does not change, or changes only minimally, since both the electrode and the seismic mass are attached to the substrate in a common, and in particular a comparatively small, area.The connection area and the expansion area are thereby bent in the same way, so that, in particular, the relative distance between the electrode and the seismic mass does not change or changes only negligibly. Reducing the sensitivity of the sensor arrangement to mechanical stress particularly allows for comparatively cost-effective packaging of the sensor arrangement in molded packaging. In both cases, the sensitivity of the sensor arrangement is advantageously reduced, with the reduction of sensitivity to surface charges due to the symmetrically shaped underside of the seismic mass being of particular importance when the reduction of the sensor arrangement to mechanical stress is also achieved by arranging the connection area in the suspension area.This results from the fact that the bending of the substrate relative to the seismic mass leads to a change in the distance between the substrate and the seismic mass perpendicular to the principal plane of extension. Asymmetric electrostatic interactions between the seismic mass and the substrate, as a result of surface charges, can be intensified by substrate bending with respect to the axis of torsion. Therefore, a reduction in stress sensitivity must also advantageously lead to a reduction in sensitivity to surface charges. The reverse is also true.

[0007] Advantageous embodiments and further developments of the invention can be found in the dependent claims and in the description with reference to the drawings.

[0008] According to a preferred embodiment, the seismic mass has at least one mass element on a side facing away from the substrate to generate the asymmetric mass distribution, so that an asymmetric mass distribution of the seismic mass with respect to the torsion axis is advantageously achieved, although the side facing the substrate has a symmetric geometry with respect to the torsion axis. The mass element is deposited, in particular, on the side of the seismic mass facing away from the substrate using an epitaxial process.

[0009] According to a further preferred embodiment, a compensation element is arranged on the side facing away from the substrate, with the torsion axis preferably arranged parallel to the main extension plane between the mass element and the compensation element. The compensation element is particularly advantageous for compensating electrostatic interactions caused by the mass element. In particular, the compensation element compensates for parasitic electrical capacitances on the side of the mass element. The compensation element is preferably lighter than the mass element, so that the compensation element does not compensate for the mass element's weight on the other side of the torsion axis.The electrostatic interactions to be compensated by the compensation element include, in particular, electrostatic interactions between the mass element and a stationary electrode, which is arranged perpendicular to the principal plane of extension, preferably below or above the seismic mass, and parallel to the principal plane of extension, preferably next to the mass element. Corresponding and equally large electrostatic interactions are generated on the other side of the axis of torsion between the compensation element and a further stationary electrode, which is preferably arranged analogously to the electrode. The sum of the electrostatic interactions is therefore zero or essentially zero.

[0010] According to a further preferred embodiment, the seismic mass has a first and a second interaction surface, wherein the first interaction surface is associated with a stationary electrode and the second interaction surface with a stationary additional electrode, and wherein the size of the first interaction surface is equal to the size of the second interaction surface, and wherein, in particular, the geometric shape of the first interaction surface is equal to the geometric shape of the second interaction surface. This advantageously achieves a compensation of the electrostatic interactions between the first interaction surface and the electrode, and between the second interaction surface and the additional electrode.This has the particular advantage that, in addition to the electrostatic forces occurring on both sides of the torsion axis on the side of the seismic mass facing the substrate, the electrostatic interactions occurring on both sides of the torsion axis on the side of the seismic mass facing away from the substrate also cancel each other out. The sum of the effective forces acting on the seismic mass due to surface charges is therefore advantageously zero or essentially zero. A respective interaction surface within the meaning of the present invention comprises, in particular, that surface of the seismic mass which interacts electrostatically directly with the electrode or the further electrode.

[0011] According to a further preferred embodiment, the first and second interaction surfaces are designed to be symmetrical with respect to the torsion axis, wherein the first interaction surface particularly comprises regions of the side of the seismic mass facing away from the substrate and regions of the mass element, and the second interaction surface comprises further regions of the side of the seismic mass facing away from the substrate and regions of the compensation element. The first and second interaction surfaces therefore preferably comprise regions of the seismic mass, the mass element, and / or the compensation element, wherein the regions are particularly preferably oriented both parallel to and perpendicular to the main extension plane.Particularly advantageous is the compensation of the electrostatic interaction between the electrode and the mass element on one side of the torsion axis by an interaction between the further electrode and the compensation element on the other side of the torsion axis, without generating a weight compensation with respect to the torsion axis.

[0012] According to a further preferred embodiment, the distance between the suspension area and the connection area, perpendicular to the torsion axis and parallel to the main extension plane, is preferably less than 50 percent, more preferably less than 20 percent, and more preferably less than 5 percent of the maximum extent of the seismic mass perpendicular to the torsion axis and parallel to the main extension plane. This arrangement of the suspension area and the connection area on a comparatively small substrate area is particularly preferred, so that the effects of substrate deflection on the distance between the seismic mass and the electrode are comparatively small.The connection area and the suspension area are preferably arranged relatively close to the torsion axis, so that a completely symmetrical arrangement of the sensor arrangement is particularly advantageous, especially when integrating further electrodes into the sensor arrangement.

[0013] According to a further preferred embodiment, the connection area is arranged perpendicular to the torsion axis and parallel to the principal extension plane in a region of the electrode facing the torsion axis, so that the electrode can be attached as close as possible to the torsion axis by means of the connection area in a comparatively simple manner. The free-standing section of the electrode projects from the connection area preferably perpendicular and / or parallel to the torsion axis over a portion of the seismic mass, so that an overlap is created perpendicular to the principal extension plane between one of the sides of the seismic mass separated by the torsion axis and the free-standing section of the electrode.

[0014] According to a further preferred embodiment, the area of ​​the connection region parallel to the main extension plane is smaller than the area of ​​the electrode parallel to the main extension plane. A particularly advantageous benefit of a connection region that is as small as possible is that it minimizes the mechanical stress in the connection region when the substrate bends.

[0015] According to a further preferred embodiment, the electrode is arranged perpendicular to the principal extension plane between the seismic mass and the substrate, or the seismic mass is arranged perpendicular to the principal extension plane between the electrode and the substrate. This particularly advantageously enables the measurement of a displacement of the seismic mass relative to the substrate using electrodes below the seismic mass and / or using electrodes above the seismic mass. Electrodes arranged above the seismic mass are realized, in particular, by means of an additional epitaxial layer, which is deposited above the seismic mass during the manufacturing process of the sensor assembly.It is particularly preferred that the displacement of the seismic mass is measured both with electrodes above the seismic mass and with additional, in particular essentially identical, electrodes below the seismic mass. This advantageously enables a fully differential evaluation of the displacement movement on only one side of the torsional axis.

[0016] According to a further preferred embodiment, the sensor arrangement includes an additional electrode which is identical in construction to the electrode and which is arranged in a mirror-symmetrical manner with respect to the axis of torsion, so that a fully differential evaluation of a deflection of the seismic mass is advantageously possible with electrodes on only one side of the seismic mass.

[0017] According to a further preferred embodiment, the connection area is arranged substantially centrally along the torsion axis with respect to the seismic mass. This particularly preferentially reduces the influence of such substrate deflections on the geometry of the sensor arrangement, which has an axis parallel to the main extension plane and perpendicular to the torsion axis.

[0018] Exemplary embodiments of the present invention are shown in the drawings and explained in more detail in the following description. Brief description of the drawings

[0019] They show Fig. 1 a schematic perspective view of a sensor arrangement according to a first embodiment of the present invention, Fig. 2 a schematic perspective view of a sensor arrangement according to a second embodiment of the present invention, Fig. 3 a schematic top view of a sensor arrangement according to a third embodiment of the present invention, Fig. 4 a schematic perspective view of a sensor arrangement according to a fourth embodiment of the present invention, Fig. 5a and Fig. 5b two schematic perspective views of a sensor arrangement according to a fifth embodiment of the present invention, Fig. 6 a schematic perspective view of a sensor arrangement according to a sixth embodiment of the present invention, Fig. 7 a schematic top view of a sensor arrangement according to a seventh embodiment of the present invention, Fig. 8 a schematic perspective view of a sensor arrangement according to an eighth embodiment of the present invention and Fig. 9 a schematic perspective view of a sensor arrangement according to a ninth embodiment of the present invention. Embodiments of the invention

[0020] In the various figures, identical parts are always marked with the same reference symbols and are therefore usually only named or mentioned once.

[0021] In Fig. Figure 1 is a schematic perspective view of a sensor arrangement 1 according to a first embodiment of the present invention, wherein the sensor arrangement 1 comprises a substrate 2 which is shown exaggeratedly bent relative to its main extension plane 100 to illustrate mechanical stress. Furthermore, the sensor arrangement 1 comprises a seismic mass 3 which is attached to the substrate 2 in a suspension area 5 such that the seismic mass 3 is rotatable about a torsion axis 6 relative to the substrate 2, wherein the suspension area 5 in particular comprises a bending and / or torsion spring. The seismic mass 3 has a mass element 10 on one side of the torsion axis 6, which creates an asymmetric mass distribution of the seismic mass 3 with respect to the torsion axis 6. This results in a torque acting on the seismic mass 3 when the sensor arrangement 1 is accelerated perpendicular to the main extension plane 100.A deflection of the seismic mass 3 is capacitively evaluated by means of an electrode 4 and a further electrode 4', wherein the electrode 4 and the further electrode 4' are arranged "above" the seismic mass 3, i.e., the seismic mass 3 is arranged perpendicular to the principal extension plane 100 between the substrate 2 and the electrode 4 and the further electrode 4', respectively. The electrode 4 is designed as a cantilevered electrode, which is attached to the substrate 2 by means of a connection area 7. In order to minimize the influence of the deflection of the substrate 2 on the geometry between the seismic mass 3 and the electrode 4, i.e., in particular on the distance between the seismic mass 3 and the electrode 4 perpendicular to the principal extension plane 100, the connection area 7 is arranged in the area of ​​the suspension area 5.The connection area 7 is arranged in a region of the electrode 4 facing the torsion axis 6, such that the distance between the torsion axis 6 and the connection area 7 perpendicular to the torsion axis 6 and parallel to the principal extension plane 100 is minimized. The area of ​​the connection area 7 parallel to the principal extension plane 100 is many times smaller than the area of ​​the electrode 4. The further electrode 4' is essentially identical in construction to the electrode 4, wherein the further electrode 4' is mirror-symmetrical to the electrode 4' with respect to the torsion axis 6, so that the further electrode 4' is attached to the substrate 2 by a further connection area 7', which is also arranged in the region of the suspension area 5. The sensor arrangement 1 comprises, in particular, a sensor extending in the z-direction, i.e.,Perpendicular to the main extension plane, 100 sensitive acceleration sensors are arranged, the sensor arrangement preferably being designed for packaging in a mold housing. In an alternative embodiment (not shown), the electrodes 4 and the further electrodes 4' are arranged between the seismic mass 3 and the substrate 2, or, in addition to the electrode 4 and the further electrode 4' according to the first embodiment, an additional electrode 44 and an additional further electrode 44' are arranged between the seismic mass 3 and the substrate 2. In a further alternative embodiment, the electrode 4 or the further electrode 4' each has a plurality of connection areas 7 or a plurality of further connection areas 7', respectively. Particularly preferably, the electrode 4 or the further electrode 4' has exactly two connection areas 7 or 8.Exactly two further connection areas 7' are provided, which are arranged parallel to the torsion axis 6 on both sides of the seismic mass 3. The seismic mass 3 is particularly preferably also attached to the substrate 2 by means of exactly two suspension areas 5, wherein one suspension area 5 is arranged along the torsion axis 6 on one of the two sides of the seismic mass 3.

[0022] In Fig. Figure 2 shows a schematic perspective view of a sensor arrangement 1 according to a second embodiment of the present invention, wherein the second embodiment is essentially identical to that shown in Fig. The first embodiment illustrated in Figure 1 is characterized in that the seismic mass 2, for generating the mass distribution asymmetric with respect to the torsion axis 6, does not have a mass element 10, but instead has an extension 3' on one side of the torsion axis 6. This extension 3' of the seismic mass 3 also ensures an asymmetric mass distribution of the seismic mass 3 with respect to the torsion axis 6. The sensor arrangement 1 according to the second embodiment has the advantage over the sensor arrangement 1 according to the first embodiment that the seismic mass 3 is less sensitive to accelerations acting parallel to the torsion axis 6, since in this case no torque acts about a further axis of rotation perpendicular to the torsion axis 6.

[0023] In Fig. Figure 3 shows a schematic top view of a sensor arrangement 1 according to a third embodiment of the present invention, wherein the third embodiment is essentially identical to that shown in Figure 3. Fig. 2 illustrated second embodiment, wherein the seismic mass 3 has a central opening 3" in the region of the torsion axis 6 and wherein the suspension area 5, the connection area 7 and the further connection area 7' are arranged in the central opening 3" such that the suspension area 5, the connection area 7 and the further connection area 7' are arranged parallel to the torsion axis 6 centrally with respect to the seismic mass 3.

[0024] In Fig. Figure 4 shows a schematic perspective view of a sensor arrangement 1 according to a fourth embodiment of the present invention, wherein the fourth embodiment is essentially identical to that shown in Figure 4. Fig. 2 illustrated second embodiment, wherein the electrode 4 and the further electrode 4' are arranged between the seismic mass 6 and the substrate 2.

[0025] In the Fig. 5a and Fig. Figure 5b shows two schematic perspective views of a sensor arrangement 1 according to a fifth embodiment of the present invention, the fifth embodiment being essentially identical to that shown in Fig. 3 illustrated third embodiment, wherein the electrode 4 and the further electrode 4' are arranged between the seismic mass 6 and the substrate 2.

[0026] In Fig. Figure 6 shows a schematic perspective view of a sensor arrangement 1 according to a sixth embodiment of the present invention, wherein the sixth embodiment is essentially identical to that shown in Figure 6. Fig. In the first embodiment illustrated in Figure 1, a surface of the seismic mass 3 facing the substrate 2, i.e., the underside of the seismic mass, is symmetrical with respect to the torsion axis 6, meaning that both the surface area and the geometry of the surface are identical on both sides of the torsion axis 6. In particular, this results in the parasitic electrical capacitances being equal on both sides of the torsion axis 6. Surface charges, which, for example, accumulate on the underside of the seismic mass 3 during the manufacturing process and thereby cause an electrostatic interaction between the underside of the seismic mass 3 and the substrate 2, are also symmetrically arranged with respect to the torsion axis 6 and therefore do not exert any effective torque on the seismic mass 3. Preferably, the underside of the surface shown in Figure 1 is symmetrical with respect to the torsion axis 6. Fig. The seismic mass 2 shown in Figure 1 in the sensor arrangement 1 according to the first embodiment is also symmetrical with respect to the torsion axis 6. Furthermore, in contrast to the first embodiment, the seismic mass 3 of the sixth embodiment has a compensation element 11, which is arranged with respect to the torsion axis 6 on a side of the seismic mass 3 opposite the side having the mass element 10. On the side of the seismic mass 3 having the mass element 10, the seismic mass 3 has a first interaction surface 40, which comprises at least a first sub-region 41 of the seismic mass 3 parallel to the principal extension plane 100 and a second sub-region 42 of the mass element 10 perpendicular to the principal extension plane 100 and parallel to the torsion axis 6, and which is associated with the electrode 4.In order to achieve a symmetrical distribution of the electrostatic interaction forces with respect to the torsion axis 6 in a rest position of the seismic mass 3, in addition to the asymmetrical mass distribution, the seismic mass 3 has the compensation element 11. The compensation element 11 is constructed such that at least a third sub-region 41' of the seismic mass 3 parallel to the principal extension plane 100 and a fourth sub-region 42' of the compensation element 11 perpendicular to the principal extension plane 100 and parallel to the torsion axis 6 form a second interaction surface 40', which has essentially the same geometry and area as the first interaction surface 40. The first and the second interaction surfaces 40, 40' are thus symmetrical with respect to the torsion axis 6.

[0027] In Fig. Figure 7 shows a schematic top view of a sensor arrangement 1 according to a seventh embodiment of the present invention, wherein the seventh embodiment is essentially identical to that shown in Figure 7. Fig. 6 illustrated sixth embodiment, wherein the seismic mass 3 is similar to that in Fig. 3 has a central opening 3" and wherein the suspension area 5, the connection area 7 and the further connection area 7' are similar to those in Fig. 3 are arranged parallel to the torsion axis 6 centrally with respect to the seismic mass 3.

[0028] In Fig. Figure 8 shows a schematic perspective view of a sensor arrangement 1 according to an eighth embodiment of the present invention, wherein the eighth embodiment is essentially identical to that shown in Fig. In the sixth embodiment illustrated in Figure 6, an additional electrode 44 and an additional electrode 44' are arranged between the seismic mass 3 and the substrate 2 for evaluating the displacement of the seismic mass 3 relative to the substrate 2. The torsion axis 6 runs between the additional electrode 44 and the additional electrode 44'.

[0029] In Fig. Figure 9 shows a schematic perspective view of a sensor arrangement 1 according to a ninth embodiment of the present invention, wherein the ninth embodiment is essentially identical to that shown in Figure 9. Fig.8 illustrated eighth embodiment, wherein the additional electrode 44 substantially overlaps the entire area of ​​the seismic mass 3 on one side of the torsion axis 6 perpendicular to the principal extension plane 100 and wherein the additional further electrode 44' substantially overlaps the entire area of ​​the seismic mass 3 on the other side of the torsion axis 6 perpendicular to the principal extension plane.

Claims

[1] Sensor arrangement (1) comprising a substrate (2) having a principal extension plane (100), a seismic mass (3) and at least one at least partially cantilevered electrode (4), wherein the seismic mass (3) is movably attached to the substrate (2) in a suspension area (5) about a torsion axis (6) parallel to the principal extension plane (100) and wherein the seismic mass (3) has an asymmetric mass distribution with respect to the torsion axis (6) and the electrode (4) is connected to the substrate (2) in a connection area (7), wherein a surface of the seismic mass (3) facing the substrate (2) is symmetric with respect to the torsion axis (6) and the connection area (7) is arranged perpendicular to the torsion axis (6) and parallel to the principal extension plane (100) in the area of ​​the suspension area (5) or immediately adjacent to the suspension area (5). [2] Sensor arrangement (1) according to claim 1, characterized by, that the seismic mass (3) has at least one mass element (10) on a side facing away from the substrate (2) to generate the asymmetric mass distribution. [3] Sensor arrangement (1) according to claim 2, characterized by , that on the side facing away from the substrate (2) a compensation element (11) is further arranged, wherein the torsion axis (6) is preferably arranged parallel to the main extension plane (100) between the mass element (10) and the compensation element (11). [4] Sensor arrangement (1) according to one of the preceding claims, characterized by, that the seismic mass (3) has a first and a second interaction surface, wherein the first interaction surface is assigned to a stationary electrode (4) and the second interaction surface to a stationary further electrode (4') and wherein the size of the first interaction surface is equal to the size of the second interaction surface and wherein, in particular, the geometric shape of the first interaction surface is equal to the geometric shape of the second interaction surface. [5] Sensor arrangement (1) according to claims 2, 3 and 4, characterized by, that the first and second interaction surfaces are symmetrical with respect to the torsion axis (6) and in particular the first interaction surface includes areas of the side of the seismic mass (3) facing away from the substrate (2) and areas of the mass element (10) and the second interaction surface includes further areas of the side of the seismic mass (3) facing away from the substrate (2) and areas of the compensation element (11). [6] Sensor arrangement (1) according to one of the preceding claims, characterized by , that the connection area (7) is arranged perpendicular to the torsion axis (6) and parallel to the main extension plane (100) in the area of ​​the suspension area (5) and immediately adjacent to the suspension area (5). [7] Sensor arrangement (1) according to one of the preceding claims, characterized by, that the distance (8) between the suspension area (5) and the connection area (7) perpendicular to the torsion axis (6) and parallel to the principal extension plane (100) comprises less than 50 percent, preferably less than 20 percent and particularly preferably less than 5 percent of the maximum extent (9) of the seismic mass (3) perpendicular to the torsion axis (6) and parallel to the principal extension plane (100). [8] Sensor arrangement (1) according to one of the preceding claims, characterized by , that the connection area (7) is arranged perpendicular to the torsion axis (6) and parallel to the main extension plane (100) in a region of the electrode (4) facing the torsion axis (6) and / or that the area of ​​the connection area (7) parallel to the main extension plane (100) is smaller than the area of ​​the electrode (4) parallel to the main extension plane (100). [9] Sensor arrangement (1) according to any one of the preceding claims, characterized by, that the electrode (4) is arranged perpendicular to the principal extension plane (100) between the seismic mass (3) and the substrate (2) or that the seismic mass (3) is arranged perpendicular to the principal extension plane (100) between the electrode (4) and the substrate (2). [10] Sensor arrangement (1) according to any one of the preceding claims, characterized by , that an electrode (4) is arranged perpendicular to the main extension plane (100) both above and below the seismic mass (3). [11] Sensor arrangement (1) according to any one of the preceding claims, characterized by , that the sensor arrangement (1) has a further electrode (4') which is identical in construction to the electrode (4) and which is arranged in a mirror-symmetrical manner with respect to the torsion axis (6) to the electrode (4). [12] Sensor arrangement (1) according to one of the preceding claims, characterized by, that the connection area (7) is arranged substantially centrally along the torsion axis (6) with respect to the seismic mass (2).

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