MEMS element for the mechanical-electrical conversion of frequency changes into electrical signals

Abstract

The invention relates to a MEMS element (1) for the mechanical-electrical conversion of frequency changes, for example of pressure changes, of sound waves, of structure-borne sound waves and / or of ultrasonic waves, into electrical signals, the MEMS element comprising at least two oppositely differentially measuring capacitances, each consisting of at least one fixed electrode (17, 18, 19, 20) and at least one movable electrode (8, 9, 10, 11, 13, 14, 15, 16), wherein the movable electrode (8, 9, 10, 11, 13, 14, 15, 16) is coupled to a membrane arrangement (5) consisting of at least two membranes (3, 4) with a fixed spacing to one another, wherein the conversion into electrical signals is effected by a differential measurement of at least two capacitance changes which result from a mechanical change in size of an area of overlap (21-28) between the fixed electrode (17, 18, 19, 20) and the movable electrode (8, 9, 10, 11, 13, 14, 15, 16), which is defined by a lateral capacitive area between the fixed electrode (17, 18, 19, 20) and the movable electrode (8, 9, 10, 11, 13, 14, 15, 16).

Description

[0001] R. 412829

[0002] Description

[0003] title

[0004] MEMS element for the mechanical-electrical conversion of frequency changes into electrical signals

[0005] State of the art

[0006] The state of the art describes various MEMS elements and methods for converting mechanical changes, such as pressure or sound waves, into electrical signals. Already known technologies utilize capacitance for measurement, whereby the relative movements between the electrodes generate a change in capacitance, which is then converted into electrical signals.

[0007] US20220201398A1 discloses a system comprising a first membrane, a second membrane and a third membrane spaced apart from each other, wherein the second membrane is located between the first membrane and the third membrane and the second membrane comprises a plurality of openings, a sealed low-pressure chamber between the first membrane and the third membrane and a plurality of electrodes in the sealed low-pressure chamber.

[0008] The object of the present invention is to provide a MEMS element that enables improved mechanical-electrical conversion of frequency changes. This aims to increase measurement accuracy and sensitivity, as well as simplify the structure. R. 412829

[0009] - 2 -

[0010] Disclosure of the invention

[0011] The invention relates to a MEMS (microelectromechanical systems) element for the mechanical-electrical conversion of frequent changes, such as pressure changes, sound waves, structure-borne sound waves, and / or ultrasound waves, into electrical signals. The MEMS element comprises at least two oppositely differentially measuring capacitances, each consisting of at least one fixed electrode and at least one movable electrode, wherein the movable electrode is coupled to a membrane arrangement consisting of at least two membranes spaced at a defined distance from each other. The conversion into electrical signals is achieved by differentially measuring at least two capacitance changes, which result from a mechanical change in the area overlap of the fixed electrode and the movable electrode, defined by a lateral capacitive area between the fixed electrode and the movable electrode.

[0012] The MEMS element and its components can be manufactured using a micromechanical MEMS manufacturing process, for example a structuring process such as etching or grinding, and / or a coating process such as a deposition process.

[0013] Etching is a well-known structuring method in semiconductor technology and can be one of the following structuring methods: photolithography, plasma etching, chemical etching, or physical etching.

[0014] The deposition process may preferably include physical vapor deposition and / or chemical vapor deposition.

[0015] The fixed electrode is a stationary electrode that is rigidly connected to the MEMS element and whose position in the system remains unchanged. The movable electrode is an electrode that is attached to the membrane assembly and is movable relative to the fixed electrode. The membrane assembly consists of R. 412829

[0016] - 3 - at least two membranes that are a defined distance apart. The area overlap refers to the region in which the fixed electrode and the movable electrode face each other and form an electrical capacitance. The lateral capacitive area is determined by the area of ​​the fixed and movable electrodes that do not directly overlap but exhibit capacitance due to their spatial proximity. Thus, for example, when the at least one movable electrode moves relative to the at least one fixed electrode in a first direction, a first area overlap decreases, while a second, opposite area overlap increases. Similarly, when the movable electrode moves relative to the fixed electrode in the opposite direction, the first area overlap increases, while the second, opposite area overlap decreases.By measuring these differentially opposite measuring capacitances, which depend on the change in the two opposite area overlap quantities, the direction as well as the speed and acceleration of the movement of the moving electrode relative to the fixed electrode is consequently determined.

[0017] One advantage lies in the precise conversion of mechanical vibrations into electrical signals. High sensitivity and accuracy are achieved through the use of oppositely differentially measuring capacitances and the measurement of capacitance changes due to mechanical alterations. This enables the efficient conversion of pressure changes, sound waves, and other mechanical changes into electrical signals.

[0018] Advantageously, the lateral distance between the fixed electrode and the movable electrode can remain unchanged, while the capacitive area overlap between the electrodes changes, thereby causing the change in capacitance.

[0019] The lateral distance is the horizontal distance between the fixed and the movable electrode perpendicular to a direction of movement of the movable electrode relative to the fixed electrode, whereby the lateral distance remains constant during operation of the MEMS element. The change in R. 412829

[0020] - 4 -

[0021] The area overlap size is achieved through the relative movement of the electrodes to each other, without changing the lateral distance between them.

[0022] This reduces mechanical complexity, as no adjustment of the lateral distance is required, while maintaining the sensitivity of the capacitance measurement. Furthermore, it avoids potential collisions between the electrodes.

[0023] Advantageously, the MEMS element can be modularly constructed from a plurality of adjacent and / or multilayer cells, each cell comprising at least one fixed electrode and at least one movable electrode, wherein two fixed electrodes are arranged for each movable electrode such that two area overlap sizes are formed between the movable electrode and each of the two fixed electrodes, or wherein two movable electrodes are arranged for each fixed electrode such that two area overlap sizes are formed between the fixed electrode and each of the two movable electrodes.

[0024] A cell is a functional unit within the MEMS element that enables independent capacitance measurement. The cells are arranged so that they can be positioned side-by-side or in multiple layers. Each cell contains at least one fixed electrode and one movable electrode that interact to measure capacitance changes. In an arrangement with two fixed electrodes and one movable electrode, two capacitances are generated, the changes in which are detected by the mechanical movement of the movable electrode. Alternatively, the arrangement can consist of one fixed electrode and two movable electrodes that detect similar, oppositely differentially measured capacitance changes.

[0025] This increases the system's flexibility, as multiple cells can operate independently and enable higher measurement precision. Consequently, the membrane's movement can be detected not just at a single point, but across a larger area of ​​the membrane using individual cells. R. 412829

[0026] - 5 -

[0027] Advantageously, the cells can be mechanically connected and electrically separated.

[0028] Mechanically connected means that the cells are physically linked to form a unified structure. Electrically isolated means that there is no electrical coupling between the cells, allowing each cell to operate independently and acquire separate measurements. If the cells are physically connected, the membrane movement can preferably be determined by averaging the individual cell measurements.

[0029] This results in a stable mechanical structure while avoiding electrical interference between individual cells.

[0030] Advantageously, the membrane arrangement can have a cavity between the two membranes, which is provided with a negative pressure suitable for the vibration capability of the system.

[0031] The cavity is the space between the membranes, which is filled with a vacuum to improve the membranes' ability to vibrate. The vacuum ensures that the membranes are pressed against the movable electrodes located within the cavity, thereby creating a flexible mechanical connection.

[0032] This improves the precision of the detection of mechanical vibrations of the membrane assembly, which increases the measurement accuracy of the MEMS element.

[0033] Advantageously, each individual fixed electrode and / or movable electrode can be rectangular, polygonal, round or oval in shape.

[0034] The shape of the electrodes describes the geometry of the fixed and movable electrodes, which can be rectangular, polygonal, round, or oval depending on the application. R. 412829

[0035] - 6 -

[0036] Advantageously, the fixed electrodes can be arranged in the form of a grid, wherein the leads of the fixed electrodes have sufficient stability and serve as a suspension, with a group of the first leads of a proportion of the fixed electrodes running orthogonally in a first plane to a second group of the second leads of a second proportion of the fixed electrodes in a second plane.

[0037] A grid describes the arrangement of fixed electrodes in a structured, regularly repeated pattern. Leads connect the fixed electrodes and ensure their mechanical stability. The leads are arranged in two planes that run orthogonally to each other to guarantee a compact and stable structure.

[0038] This creates a robust mechanical structure that simultaneously ensures the electrical performance and stability of the system, especially in the event of external shocks.

[0039] Advantageously, the stiffness of the electrodes and their leads can be dimensioned such that a natural frequency lies outside a defined useful frequency range.

[0040] Stiffness describes the resistance of the electrodes and leads to mechanical deformation. The natural frequency is the system's resonant frequency at which it oscillates when excited. By designing the stiffness so that the resonant frequency lies outside the usable frequency range, it is ensured that the system's vibrations do not affect the measurement range. The usable frequency range is the frequency range of the diaphragm assembly's movement within which the MEMS element is intended to measure the frequency changes.

[0041] This increases the system's precision when measuring signals within the desired frequency range. R. 412829

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[0043] Advantageously, the leads of the movable electrodes can have an elasticity that allows the oscillating movements of the membrane arrangement to be carried out within a usable frequency range.

[0044] The elasticity of the supply lines describes their flexibility, which allows the supply lines to follow the movements of the membranes and to carry their vibrations without being damaged.

[0045] This extends the lifespan of the system and maintains the sensitivity of the measurements even under intense vibrations.

[0046] Advantageously, the leads of the fixed electrodes and the leads of the movable electrodes can be spatially separated from each other and have a defined distance from each other, which is chosen in such a way as to minimize parasitic capacitances as much as possible.

[0047] The spatial distance between the leads describes the distance between the leads of the fixed and movable electrodes. This distance is chosen to minimize unwanted parasitic capacitances from neighboring electrodes that could distort the measurement.

[0048] This improves measurement accuracy and reduces disturbances caused by electrical interference.

[0049] Advantageously, the leads of the fixed electrodes can be reinforced by at least one stiffening, wherein the stiffening is advantageously alternately in a checkerboard pattern or continuously in the shape of a rectangle.

[0050] A stiffener between the fixed electrodes serves to increase the mechanical stability of the leads leading to the fixed electrodes. The stiffener can be designed in various geometric shapes, such as checkerboard or rectangular, to ensure the desired stability. R. 412829

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[0052] Advantageously, the at least one movable electrode in a central region of the membrane arrangement can be connected via a support to an upper first membrane and / or to a lower second membrane of the membrane arrangement, wherein the support can in particular comprise an insulating layer for potential separation.

[0053] The support is a connecting element that links the movable electrode to the membranes. The insulating layer ensures electrical isolation between the different components to prevent electrical interference. The support thus transmits the movement of the membrane assembly to the movable electrode.

[0054] Advantageously, the membrane arrangement can have at least one through opening that connects the two membranes of the membrane arrangement, wherein an outer area is hermetically sealed against an inner cavity of the membrane arrangement, so that a pressure exchange can occur through the through opening between an upper side of the membrane arrangement and a lower side of the membrane arrangement, wherein the through opening is designed as a prismatic or otherwise shaped shell.

[0055] A continuous opening in the membrane assembly allows pressure equalization between the upper and lower sides of the membranes. The hermetic seal ensures that the negative pressure is maintained within the cavity. The shape of the opening can be prismatic or other, depending on the application requirements.

[0056] This ensures constant pressure equalization during the vibration of the membrane assembly, which improves the measurement accuracy of the MEMS element.

[0057] Advantageously, the at least two capacitors measuring opposite differential I can be arranged in a central region of the membrane arrangement, consisting of the upper membrane and the lower membrane, R. 412829

[0058] - 9 - wherein a movable electrode of each of the capacitors is attached at an upper end to the upper membrane and at a lower end to the lower membrane, so that the movable electrode also serves as a spacer between the two membranes, wherein no differentially measuring capacitors with the corresponding electrodes are attached in a peripheral edge region of the membrane arrangement, so that the membrane arrangement is freely movable in the edge region.

[0059] The arrangement of the capacitors in the central area of ​​the membranes ensures an even distribution of the mechanical load. The movable electrode simultaneously acts as a spacer between the membranes to maintain the defined distance between them. The capacitors positioned at the edges allow the membrane's edge to pivot freely and adapt flexibly to the membrane's mechanical movements.

[0060] This increases the mechanical stability in the middle area and the flexibility of the membrane arrangement in the edge area, which improves the sensitivity and accuracy of the capacitance measurements.

[0061] Brief description of the drawings

[0062] The invention is explained with reference to the following drawings:

[0063] Fig. 1 shows a schematic representation of a MEMS element;

[0064] Fig. 2 shows a schematic top view of another embodiment of the MEMS element without the covering upper membrane;

[0065] Fig. 3 shows another embodiment of the MEMS element with stiffeners; Fig. 4 shows a top view of the embodiment from Fig. 2 or from Fig. 3 with the upper membrane attached to it;

[0066] Fig. 5 shows another alternative embodiment of the MEMS element;

[0067] Fig. 6 embodiment from Fig. 5 of the MEMS element in the deflected state;

[0068] Fig. 7 shows another embodiment of the MEMS element with a fl-shaped fixed electrode structure; R. 412829

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[0070] Fig. 8 shows another embodiment of the MEMS element with multiple cells;

[0071] Fig. 9 embodiment from Fig. 8 in the deflected state.

[0072] Examples of implementation

[0073] Fig. 1 shows a schematic representation of a MEMS element 1 for the mechanical-electrical conversion of frequent changes, such as pressure changes, sound waves and / or ultrasound waves, into electrical signals. The element comprises several cells 2 arranged between a lower membrane 3 and an upper membrane 4 of a membrane assembly 5 within a vacuum cavity 6. The cell 2 is shown enlarged in the lower illustration, as indicated by the arrow. The cell 2 has a left movable cross-shaped electrode assembly 7 with a first movable electrode 8, a second movable electrode 9, a third movable electrode 10, and a fourth movable electrode 11, the individual electrodes 8-11 being physically and electrically connected to one another.The right movable, cross-shaped electrode arrangement 12 comprises a fifth electrode 13, a sixth electrode 14, a seventh electrode 15, and an eighth electrode 16 arranged opposite it, which are also physically connected to one another. The two movable electrode arrangements 7 and 12 are connected at a lower end to the lower membrane 3 and at an upper end to the upper membrane 4 of the membrane arrangement 5. The connection can be established by any connection method, whereby the negative pressure within the vacuum cavity 6 pulls the two membranes 3 and 4 together, forming a frictional connection with the two electrode arrangements 7 and 12.A first fixed electrode 17 is arranged between the two opposing movable electrodes 8 and 13, a second fixed electrode 18 is arranged between the movable electrodes 9 and 14, a third fixed electrode 19 is arranged between the movable electrodes 10 and 15, and a fourth fixed electrode 20 is arranged between the movable electrodes 11 and 16. The differential measurement of the capacitance changes is achieved by changing a first area overlap size 21 between a left side face of the first fixed electrode 17 and the first movable electrode 17. R. 412829.

[0074] - 11 -

[0075] Electrode 8, a second surface overlap size 22 opposite a right side surface of the first fixed electrode 17 and the fifth movable electrode 13, a third surface overlap size 23 between the left side surface of the second fixed electrode 18 and the second movable electrode 9, a fourth surface overlap size 24 between a right side surface of the second fixed electrode 18 and a side surface of the sixth movable electrode 14, a fifth surface overlap size 25 between the third fixed electrode 19 and the third movable electrode 10, a sixth surface overlap size 26 between the third fixed electrode 19 and the seventh movable electrode 15,a seventh area overlap size 27 between the fourth fixed electrode 20 and the fourth movable electrode 11, and an eighth area overlap size 28 between the fourth fixed electrode 20 and the eighth movable electrode 16 are detected. When the electrode arrangements 7 and 12 move downwards relative to the fixed electrodes 17-20, the first four area overlap sizes 21-24, namely the overlaps of the respective lateral surfaces as in a capacitor, are reduced, thus resulting in a decrease in capacitance, while the lower area overlap sizes 25-28 are increased, thus resulting in an increase in capacitance. In this way, both the direction and the speed and / or acceleration of the movement are detected.

[0076] 29 is precisely detected. During an opposing upward movement, the first four area overlap sizes 21-24, and thus the capacitance, are increased accordingly, while the area overlap sizes 25-28, and their capacitance, are decreased. In the present case, the electrode arrangements 7 and 12 have a shape with a main rib that is crossed by four orthogonal beams. In this embodiment, a large number of area overlap sizes, namely eight area overlap sizes 21-28, are used to measure the capacitance changes in a compact design, thus enabling precise detection of the movement 29 by means of the MEMS element 1. The fixed electrodes 17-20 of the individual cells 2 can be mechanically connected to each other and anchored relative to a base frame of the MEMS element 1. A lateral distance

[0077] 30 between the lateral surfaces of the fixed electrodes 17-20 and the movable electrodes 21-28 remains during the frequent movement 29 R. 412829

[0078] - 12 - unchanged. The fixed electrodes 17-20 and the movable electrodes 21-28 can be electrically isolated from each other, so that the respective electrode pairs can perform separate measurements of capacitance changes. In this way, the different movements 29 of the membrane arrangement 5 can be detected by means of the electrically isolated cells 2 within a central area of ​​the membrane arrangement 5.

[0079] Fig. 2 shows a schematic top view of another embodiment of the MEMS element 1 without the covering upper membrane 4, comprising an annular suspension 40. Between two opposite ends of the suspension 40, first leads 41 of the fixed electrodes 17-20 of the individual cells 2 from Fig. 1 run parallel to each other and have sufficient rigidity so that the fixed electrodes 17-20 are anchored as firmly as possible relative to the suspension 40. Second leads 42 of the movable electrodes 21-28 from Fig. 1 run orthogonally to the leads 41 of the fixed electrodes 17-20. The second leads 42 have sufficient flexibility to allow the movement 29 of the movable electrodes 21-28 together with the membrane arrangement 5 from Fig. 1.The first leads 41 and the second leads 42 are insulated from each other and spaced apart in two planes, so that even if the second leads oscillate together with the membrane assembly 5 and the movable electrodes 21-28, the second leads 42 do not come into contact with the first leads 41. This ensures the safe operation of the MEMS element 1 by preventing short circuits and damage to the leads 41 and 42. Between the upper membrane 4 and the lower membrane 3 of the membrane assembly 5, a first through opening 43, a second through opening 44, a third through opening 45, and a fourth through opening 46 are arranged in the form of a cylindrical shell, with the vacuum cavity 6 being hermetically sealed.These continuous openings 43-46 allow for rapid pressure equalization between the top and bottom of the membrane assembly 5, thus improving the detection of the movement 29 of the membrane assembly 5. The individual cells 2 are arranged in the form of a grid 47 in the central region 48 of the membrane assembly 5, with the individual cells 2 of the grid R. 412829.

[0080] - 13 -

[0081] The grid 47 can be mechanically rigidly connected to the lander, so that the grid 47 can be rigidly designed, with the flexible vibration occurring only in an edge region 49 of the membrane arrangement 5. The rigidity of the grid 47 prevents vibration of the MEMS element 1 within a usable frequency range.

[0082] Fig. 3 shows a further embodiment of the MEMS element 1, wherein, compared to the embodiment in Fig. 2, additional checkerboard-pattern stiffeners 50 of the first leads 41 for the fixed electrodes 17-20 and / or rectangular stiffeners 51 of the first leads 41 are provided to further increase the stiffness of the leads 41 and thereby further minimize or prevent the vibration of the fixed electrodes 17-20 from Fig. 1. The stiffeners 50, 51 are arranged near or directly on the suspension 40, so that the interfering capacitances caused by the stiffeners 50, 51 are sufficiently far from the cells 2 of the grid 47, so that the measurement of the capacitance changes is not affected.

[0083] Fig. 4 shows a schematic top view of the embodiment from Fig. 2 or from Fig. 3 with the upper membrane 4 of the membrane arrangement 5 attached thereon, so that only the through openings 43-46 are now visible.

[0084] Fig. 5 shows another alternative embodiment of the MEMS element 1, wherein a first area overlap 54 is formed between a single fixed electrode 52 and a first movable electrode 53 by the adjacent side surfaces, and a second area overlap 56 is formed between the single fixed electrode 52 and a second movable electrode 55. The first movable electrode 53 is electrically separated from the second movable electrode 55 by an insulator 57. Consequently, the movement 58 of the movable electrodes 53 and 55 relative to the fixed electrode 52 changes the area overlaps 54 and 56, thus causing changes in capacitance. R. 412829

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[0086] Fig. 6 shows a schematic representation of the embodiment of the MEMS element 1 from Fig. 5, wherein the movable electrodes 51 and 53 were moved downwards, thereby increasing the first area overlap size 52 and decreasing the second area overlap size 54.

[0087] Fig. 7 shows a schematic representation of another embodiment of the MEMS element 1, which has an H-shaped fixed electrode structure 60 with a left electrode 61 and a right electrode 62, wherein area overlap sizes 65,66 are also formed between the left electrode 61 and movable electrodes 63 and 64, and wherein two further area overlap sizes 70 and 71 are formed between the right electrode 62 and further movable electrodes 67 and 68.

[0088] Fig. 8 shows a schematic representation of another embodiment of the MEMS element 1, wherein a single cell 2 from Fig. 7 is replicated and the individual cells 2 are arranged side by side. The H-shaped fixed electrode structures 60 of the individual cells 2 can be mechanically connected to one another, and the movable electrodes 63, 64, 67, and 68 of the individual cells can also be mechanically connected to one another. In this way, movement 69 of the movable electrodes 63, 64, 67, and 68 relative to the fixed electrode structures 60 is detected more accurately. Even if individual cells 2 malfunction, the measurement can be continued using the remaining functional cells, thus improving the service life and reliability of the MEMS element 1.

[0089] Fig. 9 shows the embodiments of the MEMS element 1 from Fig. 8 in a downwardly pivoted state, wherein the first area overlap sizes 72 of the upper movable electrodes 63, 67 are increased and the second area overlap sizes 73 of the lower movable electrodes 64, 68 are decreased.

Claims

R. 412829 - 15 - Claims 1. MEMS element (1) for the mechanical-electrical conversion of frequent changes, such as pressure changes, sound waves, structure-borne sound waves, and / or ultrasound waves, into electrical signals, comprising: at least two oppositely differentially measuring capacitances, each consisting of at least one fixed electrode (17, 18, 19, 20) and at least one movable electrode (8, 9, 10, 11, 13, 14, 15, 16), wherein the movable electrode (8, 9, 10, 11, 13, 14, 15, 16) is coupled to a membrane arrangement (5) consisting of at least two membranes (3, 4) at a defined distance from each other, wherein the conversion into electrical signals is carried out by a differential measurement of at least two capacitance changes, which are caused by a mechanical change in an area overlap size (21-28) between the fixed electrode (17, 18, 19, 20) and the movable electrode (8, 9, 10, 11, 13, 14, 15, 16) results,which is defined by a lateral capacitive surface between the fixed electrode (17, 18, 19, 20) and the movable electrode (8, 9, 10, 11, 13, 14, 15, 16).

2. MEMS element according to claim 1, characterized in that the lateral distance (30) between the fixed electrode (17, 18, 19, 20) and the movable electrode (8, 9, 10, 11, 13, 14, 15, 16) remains unchanged, whereby the capacitive area overlap size (21-28) between the electrodes changes and thereby brings about the change in capacitance.

3. MEMS element according to one of the preceding claims, characterized in that the element is modularly constructed from a plurality of adjacent and / or multilayer cells (2), wherein each cell (2) comprises at least one fixed electrode (17, 18, 19, 20) and at least one movable electrode (8, 9, 10, 11, 13, 14, 15, 16), wherein two fixed electrodes (17, 18, 19, 20) are arranged for each movable electrode (8, 9, 10, 11, 13, 14, 15, 16) such that two area overlap sizes (21-28) are provided between the movable electrode (8, 9, R. 412829 - 16 - 10, 11, 13, 14, 15, 16) and each of the two fixed electrodes (17, 18, 19, 20) are formed, or wherein two movable electrodes (63, 64, 67, 68) are arranged to each fixed electrode (61, 62) such that two area overlap sizes (65, 66, 69, 70) are formed between the fixed electrode and each of the two movable electrodes.

4. MEMS element according to claim 3, wherein the cells (2) are mechanically connected to each other and electrically separated from each other.

5. MEMS element according to one of the preceding claims, wherein the membrane arrangement (5) has a cavity (6) between the two membranes (3, 4) which is provided with a negative pressure suitable for the vibration capability of the system.

6. MEMS element according to any of the preceding claims, wherein each individual fixed electrode (17, 18, 19, 20) and / or movable electrode (8, 9, 10, 11, 13, 14, 15, 16) is rectangular, polygonal, round or oval in shape.

7. MEMS element according to one of the preceding claims, wherein the fixed electrodes (17, 18, 19, 20) are arranged in the form of a grid (47), wherein leads (41) of the fixed electrodes have sufficient stability and serve as a suspension, wherein a group of the first leads (41) of a proportion of the fixed electrodes (17, 18, 19, 20) run in a first plane orthogonally to a second group of the second leads of a second proportion of the fixed electrodes (17, 18, 19, 20) in a second plane.

8. MEMS element according to claim 7, wherein the stiffness of the fixed electrodes (17, 18, 19, 20) and / or movable electrodes (8, 9, 10, 11, 13, 14, 15, 16) with their leads (41, 42) is dimensioned such that a natural frequency lies outside a defined useful frequency range. R. 412829 - 17 - 9. MEMS element according to claim 7 or 8, wherein leads (42) of the movable electrodes (8, 9, 10, 11, 13, 14, 15, 16) have an elasticity that allows the oscillating movements of the membrane arrangement (5) to be carried out within a useful frequency range.

10. MEMS element according to one of the preceding claims, wherein the leads (41) of the fixed electrodes (17, 18, 19, 20) and the leads (42) of the movable electrodes (8, 9, 10, 11, 13, 14, 15, 16) are spatially separated from each other and have a defined distance from each other which is chosen to minimize parasitic capacitances as much as possible.

11. MEMS element according to one of the preceding claims, wherein the leads (41) of the fixed electrodes (17, 18, 19, 20) are reinforced by at least one stiffening (50, 51), wherein the stiffening (50, 51) is advantageously alternately in a checkerboard pattern or continuously in a rectangular shape.

12. MEMS element according to one of the preceding claims, characterized in that the at least one movable electrode (8, 9, 10, 11, 13, 14, 15, 16) is connected in a central region (48) of the membrane arrangement (5) via a support to an upper first membrane (4) and / or to a lower second membrane (3) of the membrane arrangement (5), wherein the support in particular comprises an insulating layer for potential separation.

13. MEMS element according to one of the preceding claims, wherein the membrane assembly (5) has at least one through opening (43, 44, 45, 46) connecting the two membranes (3, 4) of the membrane assembly (5) to each other, wherein an outer region is hermetically sealed against an inner vacuum cavity (6) of the membrane assembly (5), such that a pressure change between an upper side of the membrane assembly (5) and a lower side of the R. 412829 - 18 - Membrane arrangement (5) is carried out, wherein the through opening is designed as a prism-shaped or otherwise shaped sheath.

14. MEMS element according to one of the preceding claims, wherein the at least two oppositely differentially measuring capacitors are arranged in a central region (48) of the membrane arrangement (5), consisting of the upper membrane (4) and the lower membrane (3), wherein a movable electrode (8, 9, 10, 11, 13, 14, 15, 16) of each of the capacitors is attached at an upper end to the upper membrane (4) and at a lower end to the lower membrane (3), such that the movable electrode (8, 9, 10, 11, 13, 14, 15, 16) also serves as a spacer between the two membranes (3, 4), wherein no differentially measuring capacitors with the corresponding electrodes are attached in a peripheral edge region (49) of the membrane arrangement (5), such that the membrane arrangement in The edge area (49) is freely movable.

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