MEMS component

Abstract

The invention relates to a MEMS component, comprising: a support, a drive element which can move along a movement direction and is elastically suspended on the support and which has at least one individually electrically actuatable drive electrode, a displacement plate which is connected to the drive element, and a stationary actuator assembly which has a plurality of individually electrically actuatable actuator electrodes that are electrically insulated from one another and are arranged one after the other along the movement direction of the movable drive element, wherein the actuator electrodes are designed to generate an electric stray field upon being electrically actuated so that when the at least one drive electrode is electrically actuated, the drive electrode is subjected to an electrostatic force oriented along the movement direction. The invention also relates to a method for operating a MEMS component, to a computer program, and to a machine-readable storage medium.

Description

[0001] Description

[0002] title

[0003] MEMS component

[0004] The invention relates to a MEMS component, a method for operating the MEMS component, a computer program and a machine-readable storage medium.

[0005] State of the art

[0006] The fundamental goal, or rather the challenge, of MEMS-based loudspeakers is to achieve the highest possible SPL (sound pressure level). A high SPL is associated with a high displaced air volume. At the same time, the chip area should be kept as small as possible for cost reasons, so the SPL / chip area ratio must be optimized or increased. Known concepts for MEMS-based loudspeakers are briefly listed below.

[0007] Current MEMS loudspeakers are mostly designed as planar structures, with an oscillating membrane or a cantilever beam being excited in such a way that the displacement and / or compression of the fluid occurs vertically to the membrane plane and the main extension plane of the component. Such membranes are typically excited by a piezoelectric or (quasi)electrostatic drive. One such design is disclosed, for example, in US2021297787. Due to the clamping of the membrane or cantilever beam(s), maximum deflection is limited. These systems therefore have the disadvantage that they require a large membrane area to displace a large fluid volume, which results in a large chip area for the MEMS component. A further limitation of the displaceable air volume is due to the membrane being circumferentially connected or clamped to the substrate material.Due to this circumferential clamping, the local deflection amplitude of the membrane varies across the membrane's surface (in the clamped edge region, the deflection is virtually zero, while it is typically maximum in the center of the membrane). Such uneven deflection of the membrane surface further reduces the displaced air volume and increases total harmonic distortion (THD). Ideally, however, a planar, cylindrical deflection (“piston mode”) of the sound-generating surface would be desirable. US2021297787 proposes membrane structures that reduce the uneven deflection to a certain extent or increase the area of ​​maximum deflection by providing a torsion-resistant “membrane plate” in the center of the membrane, which is embedded circumferentially in the actual membrane that functions as the actuator.

[0008] In general, corresponding MEMS loudspeakers with such a planar structure or membrane have a fluidically effective area that is, in principle, smaller than the chip area. This means that an increase in the air volume to be displaced inevitably entails an increase in the chip area.

[0009] The prior art therefore proposes concepts that do not have a single membrane with vertical vibration, but rather several laterally or horizontally movable elements that extend in the vertical direction. The advantage here is that the displaced volume of the fluid not only scales with the chip area, but can also be influenced by the vertical dimension. By vertically erecting and arranging a plurality of membranes or bending beams, the fluidically effective surface is multiplied and can be significantly larger than the actual chip area. MEMS loudspeakers based on this basic concept are disclosed, for example, in WO 2021 / 144400, W0002021223886 or DE 102019203 914, as well as in Kaiser et al. Microsystems & Nanoengineering (2019) 5:43.

[0010] W0002021223886 describes a concept that proposes the separation of an active drive structure and a passive displacement structure, with the two structures arranged one above the other (e.g., as a wafer stack). In other words, both structures (drive and displacement) overlap in the same surface area. These two structures can be mechanically connected via a coupling element, so that a deflection of the active structure results in a movement of the passive displacement structure.

[0011] WO22117197 discloses a microfluidic component with vertical displacement elements that is driven by means of electrical stray fields. The displacement elements are laterally clamped on both sides. The electrical stray fields are formed via electrodes that are arranged on both the underside of the cover substrate and the top side of the base substrate. The electrodes are thus aligned with the displacement structure located between them and are as close as possible to the displacement elements. The displacement elements are therefore located on their front sides (top and bottom of the displacement elements) in the stray field of the electrodes (the stray field or the electrical field between the electrodes has a directional component vertical to the surface of the electrodes and therefore parallel to the main plane of extension of the displacement elements and a directional component along the deflection of the displacement elements, i.e.perpendicular to their main plane of extension. When the displacement elements are electrically controlled, the individual displacement element experiences an electrostatic force (acting on the top and bottom of the displacement structure), which causes a lateral deflection of the displacement element (due to the stray field component in the deflection direction of the displacement elements). In contrast to the concept of.

[0012] W0002021223886 the displacement elements do not form a passive displacement structure, but are actively controlled with an alternating voltage.

[0013] A disadvantage of this displacer drive concept, in addition to the high technological hurdle for industrial implementation, is the low maximum deflection of the displacer elements – this deflection is in the range of a few micrometers (due to the design principle, this deflection can only be half the distance between the fixed electrodes). Due to this low deflection, achieving a high SPL requires both numerous vertically arranged displacer elements with close spacing between them (high periodicity) and displacer elements with a high vertical extension. Both of these requirements together lead to high demands on the design (specification and tolerances) of the displacer elements, which makes technological feasibility very cost-intensive.

[0014] Disclosure of the invention

[0015] The object underlying the invention is to provide a MEMS component which, for example, enables high SPL (Sound Pressure Level) on a small component area.

[0016] The object underlying the invention is to provide a method for operating the MEMS component with which, for example, high SPL can be achieved.

[0017] The object underlying the invention is to provide a computer program.

[0018] The object underlying the invention is to provide a machine-readable storage medium.

[0019] These objects are achieved by means of the corresponding subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of the respective dependent subclaims.

[0020] According to a first aspect, a MEMS component is provided, comprising: a carrier, a drive element which is movable along a direction of movement, which is resiliently suspended on the carrier and has at least one individually electrically controllable drive electrode, a displacement plate connected to the drive element, a stationary actuator arrangement which has a plurality of actuator electrodes which are electrically insulated from one another and individually electrically controllable and which are arranged one after the other along the direction of movement of the movable drive element, wherein the actuator electrodes are configured to generate an electrical stray field when electrically controlled, such that when the at least one drive electrode is electrically controlled, it experiences a directed electrostatic force along the direction of movement.

[0021] According to a second aspect, a method for operating the MEMS device according to the first aspect is provided, comprising the following steps: electrically driving the drive electrodes to generate a stray electric field, electrically driving the at least one drive electrode to generate a directed electrostatic force along the direction of movement, such that the at least one drive electrode experiences the directed electrostatic force along the direction of movement.

[0022] According to a third aspect, a computer program is provided, comprising instructions which, when the computer program is executed by a computer, for example by the MEMS component according to the first aspect and / or by a control device, cause the computer to carry out a method according to the second aspect.

[0023] According to a fourth aspect, a machine-readable storage medium is provided on which the computer program according to the third aspect is stored.

[0024] The abbreviation "MEMS" stands for micro-electro-mechanical system.

[0025] The invention is based on and incorporates the finding that the above object is achieved by providing an actuator arrangement with a plurality of actuator electrodes arranged or lined up along a direction of movement of the drive element. By individually electrically controlling the actuator electrodes and the drive electrode, a directed electrostatic force can be generated along the direction of movement, which acts on the drive electrode so that the latter can or does perform a movement along the direction of movement due to the electrostatic force acting on it. As a result, the drive element moves, and thus also the displacement plate connected to the drive element.

[0026] Through individual control, a continuous movement or deflection of the drive element can be enabled. The drive principle is based on fixed electrodes, the actuator electrodes, which generate a stray electric field, and at least one movable electrode, the drive electrode, which is electrically controlled in such a way that it experiences a directed electrostatic force in the stray electric field along the direction of movement of the electrode. This drive principle is repeated and continued along the direction of movement of the movable electrode, so that the deflection amplitude of the drive electrode and thus also of the displacement plate is increased. The fixed electrodes are arranged repeatedly along the direction of movement of the movable electrode.It was recognized that a time-varying wiring or control of the repeatedly arranged fixed electrodes enables a perpetual deflection of the movable electrode. Furthermore, as an alternative or in addition to a time-varying wiring of the fixed electrodes, an exemplary design of the movable electrode is provided, which, for example, allows multi-phase control and thus also enables a continuous movement in combination with the perpetually configured fixed electrodes.

[0027] At this point, the following efficiency formula is defined: The term "efficiency" for MEMS-based loudspeakers will be introduced below, allowing us to compare the various conceptual approaches in terms of their advantages and disadvantages. Efficiency is defined as the displaceable air volume per chip area - E_volume. The efficiency relationship is:

[0028] E_volume = A_acoustic / A_activeChip * H_effective with

[0029] H_effective = H_max * k (example: membrane clamped on both sides k ~0.4) and with:

[0030] E_volume: “efficiency”; displaceable air volume per chip area

[0031] A_acoustic: acoustically effective surface

[0032] H_effective: effective amplitude or stroke (amplitude = deflection of the membrane)

[0033] H_max: maximum deflection or amplitude or stroke k: coefficient of average deflection to maximum deflection

[0034] A_activeChip: active chip area

[0035] Concepts with a planar membrane, such as those described in US2021 / 297787, have an acoustically effective surface area that roughly corresponds to the active chip area. This means that the factor [A_acoustic / A_activeChip] is approximately equal to 1. Such concepts therefore require a high effective amplitude and / or a large chip area for a high SPL (sound pressure level).

[0036] Concepts with a vertical alignment and multiplication of membranes increase the factor [A_acoustic / A_activeChip]. However, in addition to the aforementioned technological challenges of manufacturing such concepts, the limitation of the displaced volume due to a lower effective displacement H_effective must be considered. The effective displacement H_effective in relation to the periodicity of the vertical membranes is called the fill factor.

[0037] However, due to a variety of reasons, especially in manufacturing, this fill factor is significantly limited.

[0038] The concept described here enables a MEMS-based loudspeaker concept with high efficiency (E_volume), i.e., a high displaceable air volume per chip area, particularly taking into account technological manufacturability and reduced process complexity. As in the "efficiency formula" listed above, the maximum excursion must be increased to achieve increased SPL, regardless of the loudspeaker concept used.

[0039] The approach to achieving high efficiency lies in maximizing the maximum displacement H_max of a displacement structure: the displacement plate. For this purpose, an actuator arrangement with perpetually designed elements, the actuator electrodes, is proposed, which increases the displacement by repeatedly exploiting the actuator principle or drive principle in the displacement movement, i.e., the direction of movement.

[0040] In this case, both the maximum amplitude or deflection H_max is increased and, in one embodiment, a displacement structure with a coefficient k close to 1 is achieved.

[0041] Furthermore, the technological feasibility and simplicity of the manufacturing process is ensured by providing a planar design with a lateral movement direction in one embodiment. Such a planar design can be realized using a technology based on layer deposition, which is advantageous over a horizontal movement direction, since this necessarily requires a deep structuring technology to produce the vertically stacked actuator electrodes.

[0042] The concept described here can be applied to all MEMS-based loudspeaker concepts discussed so far (but not necessarily limited to loudspeaker applications). Due to the technologically advantageous planar design, the following and the figures describe MEMS components with a planar, vertically deflectable displacement plate. This displacement plate is designed to be torsionally rigid over its entire surface, so that the displacement of the displacement plate displaces the maximum possible fluid volume; or, expressed differently, k=1, or H_max = H_effective.

[0043] For example, the area of ​​the displacement plate is equal to (or almost equal to) the active chip area.

[0044] Using the efficiency formula introduced above and its individual factors, it can also be noted that based on this concept, or due to a significantly increased displacement H_max, the requirements for the factor [A_acoustic / A_activeChip] are reduced, for example, for loudspeaker concepts with vertically arranged displacement structures. In other words, with the help of the invention described here, for example, structure heights or the periodicity of the displacement elements can be reduced for such concepts, thus making a positive contribution to industrial feasibility.

[0045] According to one embodiment, the MEMS component comprises a control device which is configured to electrically control the at least one drive electrode and the actuator electrodes individually in such a way that the at least one drive electrode moves along the direction of movement.

[0046] This results in the technical advantage, for example, that the drive electrode and the actuator electrodes can be efficiently controlled electrically individually.

[0047] In one embodiment of the MEMS component, the control device is configured to determine a position of the at least one drive electrode, wherein the control device is configured to electrically control the at least one drive electrode and / or the actuator electrodes based on the determined position. Position determination can be performed, for example, using a high-frequency, modulated AC voltage signal (>20 kHz), which allows the capacitance between the drive electrode and adjacent actuator electrodes and thus their relative position to be determined. Alternatively or additionally, position detection can be performed via separate detection electrodes, which are arranged laterally next to the actuator electrodes in some areas.

[0048] This provides the technical advantage, for example, that the drive electrode and the actuator electrodes can be individually electrically controlled depending on their position.

[0049] In one embodiment of the MEMS component, it is provided that the control device is configured to control at least two drive electrodes in phase and / or to control the actuator electrodes in multi-phase.

[0050] This results in the technical advantage, for example, that the electrostatic drive is adapted to the deflection position of the drive electrodes and is therefore particularly efficient.

[0051] In one embodiment of the MEMS component, it is provided that the drive element has at least one opening for fluid exchange.

[0052] This provides the technical advantage, for example, that no fluid damping in the drive element counteracts the desired vertical drive movement, thus reducing the achievable SPL. Otherwise, a fluid, especially air, in the volume between the drive element and the displacement plate would be compressed or diluted, resulting in an additional damping restoring force. With at least one opening, the fluid, especially air, can flow back and forth.

[0053] In one embodiment of the MEMS component, the drive element is connected to the displacement plate by means of at least one piston. This provides the technical advantage, for example, of efficiently connecting the drive element to the displacement plate.

[0054] In one embodiment of the MEMS component, it is provided that the drive element is resiliently suspended from the carrier by means of a spring suspension having at least one spring.

[0055] This creates the technical advantage, for example, that a force is generated that counteracts the movement, so that the drive element can move back to its starting position when the electrodes are switched off.

[0056] In one embodiment of the MEMS component, it is provided that the carrier for the at least one spring comprises a movement channel within which the at least one spring is movably arranged.

[0057] This provides the technical advantage, for example, that a movement of at least one spring can be guided efficiently.

[0058] In one embodiment of the MEMS component, it is provided that, in a rest position, actuator electrodes are arranged vertically spaced from one another on both sides of the drive electrode, in particular substantially symmetrically.

[0059] This results in the technical advantage, for example, that the drive element can be actively driven from its rest position in both directions with a symmetrical electrostatic force curve.

[0060] In one embodiment of the MEMS component, the carrier has a block shape in which a recess is formed, in which the drive element and the stationary actuator arrangement are arranged. This provides the technical advantage, for example, that the drive element and the stationary actuator arrangement are arranged in a space-saving manner.

[0061] In one embodiment of the MEMS component, it is provided that an acoustic input is formed on the back of the carrier, from which at least one acoustic channel runs to the recess.

[0062] This provides the technical advantage, for example, that the movement of the drive element is not restricted by fluidic damping. Otherwise, a fluid, especially air, in the volume between the drive element and the displacement plate would be compressed or diluted, resulting in an additional damping restoring force. However, the fluid, especially air, can flow back and forth via the acoustic input, the acoustic channel, and the recess.

[0063] In one embodiment of the MEMS component, the displacement plate is arranged within a recess in the carrier, and its movement is limited to the area of ​​the recess. In other words, the peripheral edge of the carrier overhangs the displacement plate at its periphery at all times. The gap between the displacement plate and the carrier edge should be as small as possible, e.g., <10 μm, especially <5 μm.

[0064] This results in the technical advantage, for example, that acoustic sound pressure losses due to air leaks around the edge of the displacement plate are largely minimized.

[0065] In one embodiment of the MEMS component, it is provided that the carrier is arranged within a housing which has a housing opening at the rear at the acoustic input.

[0066] This provides the technical advantage, for example, that the acoustic input can efficiently fulfill its function. In one embodiment of the MEMS component, the housing is provided with an acoustic output on the front.

[0067] This provides the technical advantage that, for example, sound waves generated by the movement of the displacement plate can efficiently leave the housing and the sound is not unnecessarily shielded by the housing.

[0068] In one embodiment of the MEMS component, the displacement plate is designed to be torsionally rigid.

[0069] This results in the technical advantage, for example, that the displacement plate can efficiently generate sound waves with a low distortion factor when moving.

[0070] In one embodiment of the MEMS component, it is provided that a dielectric is arranged between the drive electrodes in order to electrically insulate the drive electrodes from one another.

[0071] This provides the technical advantage, for example, that the drive electrodes can be efficiently electrically isolated from each other.

[0072] In one embodiment of the MEMS component, it is provided that the direction of movement is a vertical direction of movement, wherein the actuator electrodes are arranged one above the other, or that the direction of movement is a lateral direction of movement, wherein the actuator electrodes are arranged next to one another.

[0073] This results in the technical advantage, for example, that suitable directions of movement are provided.

[0074] For example, the method is a computer-implemented method.

[0075] Technical features and functionalities of the MEMS component result analogously from corresponding technical functionalities and technical features of the process, and vice versa. This means, in particular, that process features result analogously from features of the MEMS component, and vice versa.

[0076] The MEMS component is, for example, configured to perform all steps of the method according to the second aspect.

[0077] For example, the control device of the MEMS component is programmed to execute the computer program.

[0078] Whenever the singular is used for the drive electrode in the description, the plural should always be read as well, and vice versa. Statements made in connection with one drive electrode apply analogously to multiple drive electrodes, and vice versa. This means, for example, that multiple individually electrically controllable drive electrodes can be provided.

[0079] The phrase “at least one” means “one or more”.

[0080] The phrase “at least one” means “one or more”.

[0081] The invention is explained in more detail below using preferred embodiments. These show:

[0082] Fig. 1 a MEMS component in a cross-sectional view,

[0083] Fig. 2 different operating states of the MEMS component of Fig. 1 ,

[0084] Fig. 3 is a cross-sectional view of the MEMS device of Fig. 1,

[0085] Fig. 4 is a plan view of the MEMS device of Fig. 3,

[0086] Fig. 5 is a cross-sectional view of the MEMS device of Fig. 1,

[0087] Fig. 6 a plane section of the MEMS component, Fig. 7 a multi-phase control of the drive electrode,

[0088] Fig. 8 a multi-phase control of the drive electrode,

[0089] Fig. 9 an in-phase control of the drive electrode,

[0090] Fig. 10 an arrangement of drive electrodes and actuator electrodes, wherein the direction of movement is a lateral direction of movement,

[0091] Fig. 11 shows a method for operating a MEMS device according to the first aspect and

[0092] Fig. 12 a machine-readable storage medium.

[0093] In the following, the same reference symbols may be used for the same features.

[0094] It should be noted here that the figures show exemplary MEMS structures in the sense of the concept described here. As already noted, the actuator concept with lined-up actuator elements, the actuator electrodes, for an (ultra-wide) deflection will be described below using a MEMS-based loudspeaker structure with a planar displacement plate as an example. Thus, the stationary actuator electrodes are arranged vertically stacked on top of each other, and the movable drive electrode executes a movement perpendicular to the main extension plane of the MEMS component or MEMS chip.

[0095] Nevertheless, the actuator concept is also intended for use in combination with MEMS loudspeaker concepts with vertically arranged displacement elements (such as WO22117197 or W0002021223886), wherein the stationary actuator electrodes are arranged in a plane and the movable drive electrode executes a lateral movement direction. Fig. 1 shows a MEMS component 101 comprising a housing 103. A carrier 105 is arranged within the housing 103, wherein the carrier 105 can be, for example, a chip.

[0096] The housing has a housing opening 107 on the rear. The carrier 105 includes an acoustic input 109. The housing 103 includes the housing opening 107 on the rear at the acoustic input 109.

[0097] The carrier 105 has a recess 111. An acoustic channel 113 runs from the acoustic input 109 to the recess 111.

[0098] The MEMS component includes a drive element 115, which is formed, for example, as a drive plate. This means that the drive element 115 is, for example, a drive plate.

[0099] The drive element 115 is movable in one direction of movement. For better illustration, a Cartesian coordinate system 117 is shown in Fig. 1, with the z-axis of the Cartesian coordinate system 117 running perpendicular to the main extension plane of the MEMS component 101. The drive element 115 is movable along this vertical z-axis of the Cartesian coordinate system 117. The direction of movement of the MEMS component 101 is thus vertical.

[0100] The drive element 115 is suspended from the support 105 via a spring suspension 119. The spring suspension comprises several springs, which are more clearly visible in the sectional view shown in Fig. 6.

[0101] The drive element 115 comprises a plurality of drive electrodes 121, each of which can be individually electrically controlled.

[0102] The drive element 115 is connected to a displacement plate 123. The displacement plate 123 is made of silicon, for example. The displacement plate 123 has a thickness of 5 μm to 10 μm, for example.

[0103] The displacement plate 123, for example, is designed to be torsionally rigid. The displacement plate 123 is mechanically connected to the drive element 115 via a piston 125. This means that when the drive element 115 moves along the z-axis of the Cartesian coordinate system 117, the displacement plate 123 will also move along the z-axis.

[0104] The drive element 117 is arranged within the recess 111 of the carrier 105.

[0105] The MEMS component 101 further comprises a stationary actuator arrangement 127, which has a plurality of electrically isolated and individually electrically controllable actuator electrodes 129. The actuator electrodes 129 are arranged one after the other along the vertical direction of movement of the movable drive element 115, in this case arranged one above the other, for example, stacked.

[0106] The fixed actuator assembly 127 is arranged within the recess 111.

[0107] The housing 103 comprises an acoustic outlet 131 on the front side, through which sound waves 133 generated due to a movement of the displacement plate 123 can exit.

[0108] The actuator electrodes 129 are configured to generate an electric stray field when electrically controlled, so that when the drive electrodes 121 are electrically controlled, they experience a directed electrostatic force along the z-axis, i.e., along the direction of movement. Thus, by appropriately controlling the actuator electrode 129 and the drive electrode 121, the drive plate 115 can be moved along the z-axis, and thus also the displacement plate 123.

[0109] Thus, the MEMS device 101 can be operated according to the method for operating a MEMS device according to the second aspect.

[0110] The MEMS component 101 is, for example, a loudspeaker. Openings 135 are provided in the drive plate 115 for fluid exchange to reduce damping.

[0111] Furthermore, bond pads 137 are provided on the carrier 105 for electrical contacting of the carrier 105. The carrier 105 can thus be electrically contacted via electrical connections 139 in order to electrically control the electrodes.

[0112] The MEMS component 101 comprises, for example, a control device (not shown) which is configured to individually control the drive electrodes 121 and the actuator electrodes 129 such that the drive electrode(s) 121 move along the z-axis, i.e., along the direction of movement.

[0113] Fig. 2 shows the MEMS component 101 at three different times during active operation, with the displacement plate 123 being deflected differently in each case.

[0114] In the left-hand illustration, the displacement plate 123 is maximally deflected in the +z direction. However, the displacement plate 123 is still within the recess 111.

[0115] In the middle illustration, the displacer plate is in a rest position, i.e. in a zero position.

[0116] In the right illustration, the displacement plate 123 is at a maximum deflection in the -z direction.

[0117] The reference numeral 201 points to a volume displacement range which is determined by the maximum possible deflection in the +z and -z directions.

[0118] Fig. 3 shows the MEMS component 101 in a cross-sectional view without the housing 103. Fig. 4 shows a top view of the MEMS component 101 according to the arrow shown in Fig. 3 with the reference numeral 301.

[0119] Fig. 5 shows a cross-sectional view of the MEMS device 101 without the package 103.

[0120] Fig. 6 shows a cross-sectional view along the line 501 drawn in Fig. 5.

[0121] In the sectional view according to Fig. 6, four springs 601, 603, 605, 607 of the spring suspension 119 can be seen, which are each arranged to move within their own movement channel 609, 611, 613, 615.

[0122] Two of the four illustrated actuator electrodes 129 can be used, for example, as detection electrodes to determine a position of the drive electrodes 121.

[0123] Fig. 7 shows an example of multi-phase control of the drive electrodes.

[0124] The reference numeral 700 indicates an arrangement of drive electrodes and actuator electrodes in the rest state, i.e. in the zero position according to the middle illustration shown in Fig. 2.

[0125] The drive electrodes 129 are each electrically insulated from each other by a dielectric 701. The same applies to the drive electrodes 121, which are also electrically insulated from each other by another dielectric 702.

[0126] This means that, for example, there is a dielectric layer between two drive electrodes 121.

[0127] This means that a dielectric layer is provided between two actuator electrodes 129. Ideally, the thickness of the further dielectric 702 in the drive element 115, i.e., the thickness of the dielectric layer between two drive electrodes 121, essentially corresponds to the combined thickness of a full dielectric layer 701, i.e., the thickness of the dielectric layer between two actuator electrodes 129, and half an actuator electrode layer, i.e., half the thickness of an actuator electrode 129, in the actuator electrode stack. Thus, at least one of the two drive electrodes 121 is always offset in the drive direction from the two nearest actuator electrodes 129.

[0128] In Fig. 7, four chronologically successive phases of a control of the individual electrodes are shown by way of example: Phase 1, identified by the reference numeral 703, Phase 2, identified by the reference numeral 705, Phase 3, identified by the reference numeral 707, and Phase 4, identified by the reference numeral 709.

[0129] The actuator electrodes 129 can be individually controlled electrically in such a way that they are either at a potential U1 or at a potential U2.

[0130] For better differentiation, the upper drive electrode 121 is additionally provided with the reference numeral 711, and the lower drive electrode 121 is additionally provided with the reference numeral 713. An electrical voltage Ubias,1 is applied to the lower drive electrode 713. An electrical voltage Ubias,2 is applied to the upper drive electrode 711.

[0131] Furthermore, a graph 715 is shown in Fig. 7, which shows a sinusoidal voltage curve at the two drive electrodes 711, 713 in arbitrary units over the deflection in the z-direction or drive direction, i.e. over a position of the drive electrodes 711, 713.

[0132] In this respect, the graph 715 shows a first sine curve 717, which shows the voltage curve Ubias,1 over a position of the lower drive electrode 713, and a second sine curve 719, which shows the voltage curve Ubias,2 over a position of the upper drive electrode 711. At the beginning, i.e., at t = 0, Ubias,1 = 1 is applied to the lower drive electrode 713 and Ubias,2 = 0 is applied to the upper drive electrode 711.

[0133] Phase 1 (phase 703) shows the state for t = 0: The upper drive electrode 711 experiences no vertical force, i.e., a force in the z-direction, since one of the actuator electrodes 129 is symmetrically located exactly opposite the upper drive electrode 711. The lower drive electrode 713, on the other hand, experiences a vertical force because it lies exactly between two actuator electrodes 129, where the static electric stray field (caused by the static electrical voltages U1, U2) is maximum.

[0134] In phase 1, the upper drive electrode 711 has no driving potential and the lower drive electrode 713 has a maximum positive driving potential.

[0135] Positive means in the + direction of the z-direction, i.e. in the direction of the upper drive electrode 711. Negative means the opposite direction relative to the + direction, i.e. in the direction of the lower drive electrode 713.

[0136] In phase 2 (phase 705) and phase 4 (phase 709), the lower drive electrode 713 is symmetrically opposite one of the actuator electrodes 129, so no force transfer occurs. In contrast, the upper drive electrode 711 is located between two actuator electrodes 129, so force transfer occurs.

[0137] In phase 2, the upper drive electrode 711 has a maximum positive driving potential and the lower drive electrode 713 has no driving potential.

[0138] In phase 4, the upper drive electrode 711 has a maximum negative driving potential and the lower drive electrode 713 has no driving potential.

[0139] In phase 3 (phase 707), the upper drive electrode 711 does not experience any vertical

[0140] Force, since one of the actuator electrodes 129 is symmetrically located exactly opposite the upper drive electrode 711. The lower drive electrode 713, on the other hand, experiences a vertical force because it lies exactly between two actuator electrodes 129, where the static electric stray field (caused by the static electrical voltages U1, U2) is maximum.

[0141] In phase 3, the upper drive electrode 711 has no driving potential and the lower drive electrode 713 has a maximum negative driving potential.

[0142] The actuator electrodes 129 alternately have different polarities, which are shown in Fig. 7 by different hatching.

[0143] According to this exemplary multi-phase control, it is intended to electrically control the drive electrodes 121 in a position-dependent manner.

[0144] Thus, a multi-phase control of the movable drive electrodes 121 takes place. The fixed actuator electrodes have an alternating polarity.

[0145] An electrode distance between two drive electrodes 121 is designed in particular such that at least one drive electrode is always located in an electrical stray field of two fixed actuator electrodes 129.

[0146] By a position-dependent electrical control of the drive electrodes 121, a recurring electrostatic force in the direction of movement and thus a continued movement can be achieved.

[0147] Fig. 8 shows an exemplary multi-phase control of the movable electrodes 121 analogous to the illustration shown in Fig. 7, so that reference is made to the corresponding statements and explanations to avoid repetition.

[0148] As a difference, according to the control shown in Fig. 8, an electrical charge reversal of the actuator electrodes is provided, which is illustrated by arrows with the reference numeral 801. Accordingly, it is provided that the polarity of the actuator electrodes 129 changes.

[0149] According to the multi-phase control shown in Fig. 8, for example, a position-dependent electrical charge transfer is provided, i.e., dependent on the position of the movable drive electrodes 121. For example, a time-varying electrical charge transfer of the actuator electrodes 129 can be provided.

[0150] In the case of a time-varying electrical charge transfer, it is particularly intended to couple or synchronize the electrical charge transfer with the movement of the movable drive electrodes 121. A specific advantage of a time-varying electrical charge transfer is that the charge only needs to be pumped around in the MEMS component and does not need to be buffered, for example, in an ASIC (application-specific integrated circuit). This reduces electrical power consumption.

[0151] Fig. 9 shows an in-phase control of the drive electrodes 121 and a multi-phase control of the fixed actuator electrodes 129.

[0152] In other words, the electrical potential of the drive electrodes 121 does not change during movement. Thus, for example, the lower drive electrode is connected to Ubias,1 and the upper drive electrode 121 is connected to Ubias,2.

[0153] The fixed actuator electrodes 129 can thus, for example, each be connected to four different potentials U1, U2, U3, U4. In this case, the actuator electrodes 129 are connected successively to U1, U2, U3, U4 and then again to U1, U2, U3, U4, and so on, depending on the number of actuator electrodes 129. Thus, according to the illustration shown in Fig. 9, in-phase control of the drive electrodes 121 with multi-phase control of the fixed actuator electrodes 129 is provided.

[0154] Fig. 10 shows an exemplary embodiment according to which the direction of movement is not a vertical direction, but a lateral direction, i.e. according to the Cartesian coordinate system 117 in the x-direction.

[0155] For clarity, not all elements of the MEMS device are shown. Schematically, several actuator electrodes 1001 and several movable drive electrodes 1003 are shown.

[0156] Depending on a corresponding control of the actuator electrodes 1001 and drive electrodes 1003, an electrostatic force can be generated which acts in the x-direction on the movable electrode 1003, so that it performs a movement along the x-direction, i.e. in the lateral direction.

[0157] In Fig. 10, six exemplary representations of the movement of the movable drive electrodes 1003 are shown, numbered 1, 2, 3, 4, 5 and 6.

[0158] Thus, Fig. 10 shows an exemplary configuration of the fixed actuator electrodes and the drive electrodes for a direction of movement in the lateral direction. Through a position-dependent electrical control of the fixed actuator electrodes 1001, i.e., dependent on a position of the drive electrodes 1003, a further movement (beyond one electrode pair of the fixed actuator electrodes 1001) can be achieved. Analogous to the vertical deflection or direction of movement, the multi-phase or in-phase

[0159] Control options should be provided, as already described above.

[0160] Fig. 11 shows a flow diagram of a method for operating a MEMS component according to one of the preceding claims, comprising the following steps: electrically driving 1101 the drive electrodes to generate a stray electric field, electrically driving 1103 the at least one drive electrode to generate a directed electrostatic force along the direction of movement, so that the at least one drive electrode experiences a directed electrostatic force along the direction of movement.

[0161] Fig. 12 shows a machine-readable storage medium 1201 on which a computer program 1203 is stored. The computer program 1203 includes instructions that, when executed by a computer, cause the computer program 1203 to execute a method according to the second aspect.

Claims

Claims 1. A MEMS component (101), comprising: a carrier (105), a drive element (115) which is movable along a direction of movement and is resiliently suspended on the carrier (105) and has at least one individually electrically controllable drive electrode (121), a displacement plate (123) connected to the drive element (115), a stationary actuator arrangement (127) which has a plurality of actuator electrodes (129) which are electrically insulated from one another and individually electrically controllable and which are arranged one after the other along the direction of movement of the movable drive element (115), wherein the actuator electrodes (129) are configured to generate an electrical stray field when electrically controlled, so that when the at least one drive electrode (121) is electrically controlled, it experiences a directed electrostatic force along the direction of movement.

2. MEMS component (101) according to claim 1, comprising a control device which is configured to individually electrically control the at least one drive electrode (121) and the actuator electrodes (129) such that the at least one drive electrode (121) moves along the direction of movement.

3. MEMS component (101) according to claim 2, wherein the control device is configured to determine a position of the at least one drive electrode (121), wherein the control device is configured to electrically control the at least one drive electrode (121) and / or the actuator electrodes (129) based on the determined position.

4. MEMS component (101) according to claim 2 or 3, wherein the control device is arranged, with at least two drive electrodes (121) to control them in phase and / or to control the actuator electrodes (129) in multi-phase.

5. MEMS component (101) according to one of the preceding claims, wherein the drive element (115) has at least one opening (135) for fluid exchange.

6. MEMS component (101) according to one of the preceding claims, wherein the drive element (115) is connected to the displacement plate (123) by means of a piston (125).

7. MEMS component (101) according to one of the preceding claims, wherein the drive element (115) is resiliently suspended from the carrier (105) by means of a spring suspension (119) having at least one spring (601, 603, 605, 607).

8. MEMS component (101) according to claim 7, wherein the carrier (105) for the at least one spring (601, 603, 605, 607) comprises a movement channel (609, 611, 613, 615) within which the at least one spring (601, 603, 605, 607) is movably arranged.

9. MEMS component (101) according to one of the preceding claims, wherein the carrier (105) has a block shape in which a recess (111) is formed, in which the drive element (115) and the fixed actuator arrangement (127) are arranged.

10. MEMS component (101) according to claim 9, wherein an acoustic input (109) is formed on the rear side of the carrier (105), from which an acoustic channel (113) extends to the recess (111).

11. MEMS component (101) according to claim 10, wherein the carrier (105) is arranged within a housing (103) which has a housing opening (107) on the rear side at the acoustic input (109).

12. MEMS component (101) according to claim 11, wherein the housing (103) has an acoustic output (131) on the front side.

13. MEMS component (101) according to one of the preceding claims, wherein the displacement plate (123) is designed to be torsionally rigid.

14. MEMS component (101) according to one of the preceding claims, wherein a dielectric (703) is arranged between the drive electrodes (121) for electrically isolating the drive electrodes (121) from one another.

15. MEMS component (101) according to one of the preceding claims, wherein the direction of movement is a vertical direction of movement, wherein the actuator electrodes (129) are arranged one above the other, or that the direction of movement is a lateral direction of movement, wherein the actuator electrodes (129) are arranged next to one another.

16. MEMS component (101) according to one of the preceding claims, wherein the displacement plate (123) is arranged within a recess in the carrier (105) and its movement is limited to the region of the recess.

17. A method for operating a MEMS component (101) according to any one of the preceding claims, comprising the following steps: electrically driving (1101) the drive electrodes (121) to generate a stray electric field, electrically driving (1103) the at least one drive electrode (121) to generate a directed electrostatic force along the direction of movement, such that the at least one drive electrode (121) experiences a directed electrostatic force along the direction of movement.

18. A computer program (1203) comprising instructions which, when executed by a computer, cause the computer program (1203) to carry out a method according to claim 17.

19. A machine-readable storage medium (1201) on which the computer program (1203) according to claim 18 is stored.

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