Microsystem and method for producing the same

Abstract

The invention relates to a microsystem comprising a first support element and a second support element, wherein the position of the first support element and the second support element relative to each other is variable. The microsystem comprises a permanent magnetic device which is connected in a mechanically fixed manner to the first support element and which is configured to generate a magnetic field. Furthermore, the microsystem comprises a sensor device which is connected in a mechanically fixed manner to the second support element and which is configured to detect the magnetic field and to provide a sensor signal based on the magnetic field. The sensor signal is indicative of the relative position of the support elements relative to each other.

Description

TECHNICAL FIELD

[0001] The present invention relates to a microsystem and a production method thereof, wherein a microsystem comprising a permanent magnetic element is particularly described. Further, the present invention relates to a magnetic position detection for MEMS. BACKGROUND

[0002] In many MEMS (Micro Electro Mechanical System) applications, it is required to monitor the position of a movable microstructure precisely, e.g. as a control signal in a closed loop. In particular, capacitive, piezoresistive or piezoelectric sensor elements are used herein which can be integrated in the MEMS component. However, monitoring large travel distances and tilts in the most narrow spaces can only be done to a limited extent. A magnetic position detection based on observing the magnetic field of a permanent magnet mounted on the movable structure is an alternative. There are solutions based on using conventional micro magnets mounted hybrid. However, these are not suitable for large scale applications.

[0003] A frequently used technique is capacitive position detection using a pair of planar or comb electrodes, wherein one of the electrodes is arranged at the movable element, like Figure 14a and Figure 14b schematically shown in. Figure 14a A three-dimensional movable platform (3D stage) 1002 is shown which can be moved relative to a counter electrode or ground electrode 1004 and can be driven by actuators 10061-10064. In contrast, Figure 14b A MEMS scanner is shown, wherein a micro mirror 1008 can be deflected via a torsion beam 1012 and comb electrodes 10141. This means Figure 14a and Figure 14b An example of a MEMS element with electrostatic driving and capacitive position detection when using interdigital structures (comb electrodes, comb drive actuators) is shown. The main advantage is the easy integration into the MEMS element, since the available manufacturing processes and the availability of integrated circuits allow resolutions in the range of a few fF (femto Farad). However, capacitive position detection is only suitable for very small travel distances, since the capacitance is proportional to the inverse of the electrode distance, thus rapidly decreasing with increasing electrode distance in a simple parallel plate configuration. An improvement is provided using comb structures which keep the electrode distance constant. In this case, the capacitance signal is proportional to the overlap of the comb areas. Due to the required precision in manufacturing, the manufacturable comb structures are highly limited from a geometrical point of view, which in turn means that the monitorable travel distance is limited. In a 3D platform according to Figure 14a for example, as described in [1], the values in x- and y-direction are 12.5 pm, while in z-direction 3.5 pm. In a MEMS scanner according to Figure 14bIn MEMS scanners of the type described in [2], a (mechanical) tilt angle of up to 20° is monitored. Only a few capacitive position detection applications are inertial sensors and MEMS scanners.

[0004] Piezoresistive position detection is an alternative. Compared to capacitive detection, a larger travel distance can be monitored. However, integrating piezoresistors in a MEMS device requires considerable complexity when compared to the electrodes required for capacitive detection. Furthermore, four resistors are connected to form a Wheatstone measurement bridge to increase the sensitivity, which increases the space requirement. For example, for a MEMS scanner described in [3] and allowing position detection in the x / y plane, for example, a total of 16 piezoresistors are required.

[0005] A major disadvantage of capacitive and piezoresistive position detection is that signal detection cannot be performed in a contactless manner, but requires an electrical and mechanical connection to the sensor element, i.e. a special elastic structure within the MEMS device is required. The required elastic structure becomes larger with increasing travel distance to allow the corresponding deformation. Furthermore, in both cases, the result is a mechanical coupling to the driver. In the case of piezoresistive position detection, a force is also required to deform the piezoresistive element. In capacitive position detection, the force to be overcome comes from the electrostatic interaction.

[0006] Therefore, contactless optical position detection is of interest for MEMS, which is widely used in industrial applications. In [4], optical position detection is used, for example, to implement a magnetic field sensor. However, inexpensive and miniaturizable systems require the integration of a light source and a PSD (position sensing device) into the MEMS device. An example in this regard is shown in [5].

[0007] Magnetic position detection is another contactless technique. For example, classic applications are precision travel measurement or precision position determination in machine tools. The position detection here is performed according to the encoder principle, i.e. using a comparison between a predetermined pattern and a measurement waveform. Here, a magnetic linear scale and one or more magnetic field sensors that move back and forth over a small distance are used, for example, as described in Figure 15a or [6]. Figure 15aA system for magnetic position detection as shown in Fig. 1 comprises a magnetic scale or magnet scale 1016 to generate magnetic field lines 1018 detected by a magnetoresistive (MR) sensor 1022 to provide an analog signal 1024 via a connecting line 1026 to evaluate electronics 1028. The classic scale here consists mainly of a hard-magnetic oxide strip mounted on a stainless steel made bracket. With modern MR sensors and optimized measurement algorithms a positioning accuracy of 0.5 pm can be achieved. Furthermore, there are applications where the magnetic position detection is not based on the encoder principle but uses the measured absolute value. Usually the requirements on accuracy are less, for example in magnetic switches for detecting open or closed doors or windows or in sensors for detecting the filling level in a closed container. Also worth mentioning are tactile sensors for robots as shown in Fig. 1 and described in [7]. The magnet 1032 is surrounded by an elastomer 1034 and generates a magnetic field 1036 detected by a 3D Hall sensor 1038. The Hall sensor 1038 can be arranged on a rigid or solid substrate 1042. Figure 15b

[0008] Magnetic position detection plays almost no role for MEMS. The main problem is the lack of suitable micro magnets that are able to generate strong magnetic fields over long distances and that can be integrated into MEMS elements on the substrate plane. In addition to the material, the properties also depend in particular on the size of the magnet. The smaller the magnet, the steeper the gradient of the reduction of the magnet field, but also the absolute value of the flux density decreases with smaller magnets. The aspect ratio of the magnet, i.e. the ratio between the length (or height) of the magnet and its diameter (or surface area) plays an important role here. A high aspect ratio allows the use of small diameters while ensuring a constant flux density. Magnets with a diameter of more than 50 pm and an aspect ratio of at least 3: 1 would be well suited for MEMS. However, for magnets with a diameter (edge length) of more than 500 pm, a smaller aspect ratio is also acceptable. However, the deposition processes of semiconductor technology are designed only for layers of a few micrometers. The volume of a magnet produced in this way is still far below the target area. Structures with a thickness of several tens of micrometers can be electrodeposited. However, the corresponding processes are only suitable for specific magnetic materials. In [8], according to the Figure 15a ​Linear scales with particularly fine pole structures for measurement systems are produced on Si substrates by means of a CoNiP electroplating process. [9] describes a MEMS switch based on a movable microstructure made of electro-deposited FeNi, which is actuated by a magnetic field. Magnetic high-performance materials such as NdFeB or SmCo cannot be electro-deposited. For structures with a diameter or edge length of 50 pm, aspect ratios of more than 1 : 1 cannot be achieved. In

[10] it is shown that NdFeB layers with a thickness of more than 100 pm are deposited by means of pulsed laser deposition (PLD). The microstructure of these layers, however, is still not solved in these manufacturing processes. Alternatively, NdFeB micro-magnets can be produced by dispersing a solution containing the magnets,

[11] , however, with a large variation in shape and size. Filling microprints in a silicon substrate with loose magnetic powder and then fixing it, for example, using parylene coating of the substrate is an alternative

[12] . Further processing of these substrates is greatly limited due to the limited thermal stability of the organic material and the insufficient corrosion protection of the magnetic particles.

[0009] There will be a need for microsystems that allow precise and easy-to-manufacture position monitoring for large travel distances. SUMMARY

[0010] It is an object of the present application to provide a microsystem and a method for producing a microsystem that allow precise and easy-to-manufacture position monitoring for large travel distances.

[0011] This object is achieved by the subject matter of the independent claims.

[0012] The core idea of the present application is to connect a permanent magnetic device to a support element of the microsystem in a mechanically fixed manner, which can be done easily and precisely. This allows precise position monitoring for large travel distances.

[0013] According to one aspect of the present application, the permanent magnetic device is provided by an aggregate of magnetic particles. For example, the magnetic particles can be connected by atomic layer deposition to form a fixed (or rigid or solid) structure, wherein the solid structure can be connected to the support element in a mechanically fixed manner at the same time using a coating. Regions or cavities can be precisely manufactured in the support substrate, allowing precise adjustment of the volume filled by the particles and thus also of the volume and geometry and aspect ratio of the permanent magnetic device. Subsequent atomic layer deposition on the filled magnetic particles allows precise introduction of the magnetic structure into the support element or arrangement of the magnetic structure on the support element in a simple and reproducible manner.

[0014] According to an embodiment, a method for producing a microsystem comprises arranging a first support element and a second support element such that a relative position between the first support element and the second support element is variable. The method comprises connecting a magnetic device in a mechanically fixed manner to the first support element, the magnetic device being configured to generate a magnetic field. The method comprises connecting a sensor device, the sensor device being configured to detect the magnetic field and to provide a sensor signal based on the magnetic field. The sensor device is connected in a mechanically fixed manner to the second support element. The method is performed such that the sensor signal is indicative of the relative position between the support elements.

[0015] Preferred embodiments of the present application are defined in the dependent claims. BRIEF DESCRIPTION OF DRAWINGS

[0016] Embodiments of the present application will be discussed in more detail below with reference to the attached claims, wherein:

[0017] Figure 1 Axial magnetic flux density B of a micro-magnet sintered from NdFeB (Neodymium-Iron-Boron) powder according to an embodiment is shown z an exemplary simulation process;

[0018] Figure 2 A schematic side view of a microsystem according to an embodiment is shown;

[0019] Figure 3a A schematic perspective view of a microsystem according to an embodiment is shown, exemplarily comprising four permanent magnets;

[0020] Figure 3b A schematic side cross-sectional view of a portion of a microsystem according to an embodiment is shown;

[0021] Figure 4a to Figure 4b Simulation results for illustrating the influence of a micro-magnet on a single Hall sensor according to the present application are shown;

[0022] Figure 5a to Figure 5b A schematic graph of a magnetic field process of a sensor element according to an embodiment is shown exemplarily; Figure 4a to Figure 4b

[0023] A schematic graph of a magnetic field that can be obtained at different distances from a magnet according to an embodiment is shown;

[0023] Figure 6a to Figure 6b A schematic top view of a support element according to an embodiment is shown;

[0024] Figure 7a A schematic graph of a magnetic field that can be obtained at different distances from a magnet according to an embodiment is shown;

[0025] Figure 7b A schematic top view of a support element according to an embodiment is shown;

[0026] Figure 8aA schematic graph showing the course of signal variation depending on the size of the magnet;

[0027] Figure 8b An exemplary table showing potential values ​​for crosstalk when using the magnets of the present invention;

[0028] Figure 9a shows a schematic side sectional view of a microsystem according to an embodiment, wherein a first support element is arranged to be movable relative to a second support element by a movement parallel to the z-axis and / or by a rotation about the y-axis;

[0029] Figure 9b The configuration according to the embodiment is shown Figure 9a A schematic side cross-sectional view of a microsystem, wherein as Figure 9a Alternatively or additionally to the explanation in , the first support element is configured for movement parallel to the x-axis and / or for movement with rotation around an axis parallel to the z-axis;

[0030] Figure 10a shows a schematic side sectional view of a microsystem according to an embodiment, wherein the permanent magnet arrangement exemplarily comprises a single permanent magnet and the sensor arrangement comprises a different number of sensor elements;

[0031] Figure 10b A schematic side cross-sectional view of a microsystem according to an embodiment is shown, when compared with Figure 10a The microsystem is modified when compared to the microsystem, wherein the second support element is formed to include a groove;

[0032] Figure 11 shows a schematic side sectional view of a microsystem according to an embodiment, which is implemented for correcting interfering influences;

[0033] Figure 12 shows a schematic side cross-sectional view of a microsystem with a reference magnetic field source according to an embodiment;

[0034] Figure 13 shows a schematic flow chart of a method according to an embodiment;

[0035] Figure 14a to Figure 14b An exemplary diagram showing the known concept of capacitive position detection using planar or comb-shaped electrode pairs;

[0036] Figure 15a a diagram showing a known magnetic linear scale; and

[0037] Figure 15b A schematic diagram of a known tactile sensor is shown, which consists of a magnet surrounded by an elastomer. DETAILED DESCRIPTION

[0038] Before embodiments of the present application are discussed in more detail below with reference to the accompanying drawings, it is to be noted that like elements, objects and / or structures or elements, objects and / or structures having the same or similar function or effect, are designated with the same reference numerals throughout the different drawings, making the description of these elements interchangeable or applicable to each other in different embodiments.

[0039] Some embodiments described below relate to microsystems. Microsystems generally refer to systems manufactured on a small scale in the range of millimeters, micrometers or even nanometers. While semiconductor materials are particularly suitable for such structures due to the manufacturing process, embodiments are not limited thereto and, as an alternative or in addition to semiconductor materials, in particular MEMS (Micro-Electro-Mechanical System) processes, other materials can also be used, such as metallic materials or inorganic materials, such as resins, etc.

[0040] Some embodiments described below relate to micromagnets sintered from atomic layer deposition (ALD) of powders. Such a method is described, for example, in

[13] or

[14] . The inventors have realized that such a method provides a promising solution when applied to magnetic particles, such as those comprising NdFeB material, i.e. NdFeB powder. These can be applied, for example, to substrates, such as those comprising a semiconductor material like silicon, and can allow for extraordinary magnetic properties with good reproducibility. The inventors have found that any geometry with a structure width of, for example, between 25 pm and 2000 pm can be realized in the substrate plane. The height of the micro magnets can be, for example, up to 100 pm, 200 pm, 300 pm or more, for example, up to 500 pm.

[0041] Embodiments make use of the magnetic field of micro magnets integrated in a movable structure for position detection. Integrated in a movable structure means that the magnetic elements can be arranged, for example, in a recess of a substrate. However, this is not absolutely necessary, as it is still possible to exchange the substrate after the arrangement of the permanent magnetic means. Thus, particles can be introduced into the recess, which can be solidified, for example, and the substrate surrounding the three-dimensional structure obtained in this way can be subsequently removed to at least partially expose the permanent magnetic means. When translating and / or tilting the movable structure, the magnetic field generated by the integrated micro magnets shifts accordingly. The signals detected by an arrangement of magnetic field sensors, which can be spatially fixed, change in correspondence with the shift of the magnetic field, thus allowing conclusions to be drawn about the translation and / or tilt of the movable structure.

[0042] Figure 1 Axial magnetic flux density B of a micro magnet sintered from NdFeB (Neodymium-Iron-Boron) powder zAn exemplary simulation procedure of the example above, in three variants, each of which includes a diameter d of 50 pm, where the diameter here refers to the dimension in the plane of the substrate, like the full diameter of the cavity. The micromagnet can include a different length, which can correspond to the depth of the cavity. Procedure 21 exemplarily refers to a length of 250 pm, procedure 22 to a length of 150 pm, and procedure 23 to a length of 50 pm. It is apparent that even for procedure 23, at a distance of 600 pm, a magnetic field strength of approximately 0.1 mT can be achieved, and even higher magnetic field strengths using deeper magnets. Starting from an aspect ratio of 5:1, the increase of the flux density decreases significantly with increasing aspect ratio, however, the order of magnitude of the magnetic field strength is relatively easy to measure by modern magnetic field sensors. For example, a powder-based micromagnet array with large aspect ratio, manufactured by the patented method in

[14] , is described in

[15] , for generating two-dimensional magnetic field patterns for applications like magnetic scales.

[0043] Figure 2 A schematic side view of a microsystem 20 according to an embodiment is shown. The microsystem 20 comprises support elements 121 and 122 arranged to change their relative position to each other. This can be performed by moving the support elements 121 and / or 122 along one or more spatial directions x, y, and / or z. The support elements 121 and / or 122 can comprise the same or mutually different materials. Exemplarily, the support elements 121 and / or 122 can comprise a semiconductor material, wherein each of the support elements 121 and / or 122 can further comprise a layer sequence, wherein a semiconductor material in a doped or undoped state is alternating with other semiconductor-based materials, like insulating materials, like SiO or SiN, and / or wherein electrically conductive materials, like metallic materials, are arranged. Exemplarily, the microsystem 20 is a MEMS. The support elements alternatively or additionally comprise a glass material or a ceramic material, wherein combinations of these materials and / or combinations of these materials with other materials are also included herein.

[0044] The support element 121 is, for example, a movable support element. The support element 122 can comprise a substrate, such that the sensor signal 22 is indicative of the position of the movable support element 21 relative to the substrate 122. Alternatively, the support element 122 can be movable and the support element 121 can be a substrate and / or both support elements can be movable relative to a third structure.

[0045] The microsystem 20 comprises a permanent magnet arrangement 14 configured to generate a magnetic field 16 based on permanent magnetic properties. The permanent magnet arrangement can be fixedly connected to the support element 121 or 122, wherein a mechanical fixed connection is preferred. A mechanical fixed connection can be understood as a connection that is approximately rigid between each other. Exemplarily, the permanent magnet arrangement 14 can be arranged by a deposition method, a gluing method, or other mounting methods.

[0046] The preferred embodiment relates to the fact that the permanent magnetic device 14 is a three-dimensional structure obtained by solidifying particles by means of atomic layer deposition or the like. The deposition of such a particle coating can be used at the same time to obtain a fixed connection between the support element 121 and the permanent magnetic device 14.

[0047] The microsystem additionally comprises a sensor device 18 which is connected in a mechanically fixed manner to another one of the support elements, for example to the support element 122. The mechanically fixed connection between the sensor device 18 and the support element 122 can be obtained on the basis of a mounting process or a gluing process. The sensor device 18 is configured to detect the magnetic field 16 and to provide a sensor signal 22 which is based on the magnetic field 16. The sensor signal 22 is indicative of the relative position of the support elements 121 and 122, since the amplitude and / or other characteristics such as directional components of the magnetic field detected by the sensor device 18 are variable based on the variable relative position. The implementation allows the sensor signal 22 to unambiguously indicate the relative position of the support elements 121 and 122 with respect to each other.

[0048] Figure 3a A schematic perspective view of a microsystem 30 according to an embodiment is shown. The permanent magnetic device of the microsystem 30 can exemplarily comprise four permanent magnets 141-144. The support element 121 can exemplarily be formed as a disc or a cylinder which is supported with respect to the support element 122 via one or more spring elements 241-244. The spring elements 241-244 can exemplarily be arranged symmetrically around the support element 121, but this is not mandatory. The relative position of the support element 121 with respect to the support element 122 can be moved based on the spring elements 241-244, such as based on a rotation around one or more of the x-axis, y-axis or z-axis, and / or based on a lateral movement along one or more of these axes.

[0049] The spring elements 241 to 244 can connect or support the support element 121 with respect to the support element 122. As an alternative to the number of four spring elements, any other number greater than one can be used. At least one spring element can preset a preferred direction of movement to change the relative position between the support elements 121 and 122. Thus, a torsion spring element can exemplarily preset a torsion force, while a bending element can be deformed along a preferred bending direction and formed to be stiff along a direction perpendicular thereto. The support element 121 and / or the support element 122 can exemplarily be formed as a plate element. The plate element can exemplarily comprise or be a mirror. However, any other functionality can also be implemented. The embodiment provides a microsystem which is formed as a scanner, an electrical switch, an optical switch, a valve or a pump.

[0050] The direction of change of the relative position can be based on at least one orientation of the spring element between the support elements 121 and 122. Alternatively or additionally, the direction of change of the relative position can be based on at least one rotational axis for allowing a rotation of at least one of the support elements 121 and 122. Alternatively or additionally, the direction of change of the relative position can be based on at least one limit surface or limit edge along which a movement of the support elements 121 and / or 122 is predestined. Such a limit surface or limit edge can be a mechanical stop, for example.

[0051] Exemplarily, the support element 121 can be movable relative to the support element 122 in or parallel to an x-plane, a y-plane. The x / y-plane can thus describe a plane in which the relative position changes. At least one, several or all of the permanent magnetic elements 141 to 144 can be arranged in this plane relative to the sensor elements of the sensor device 18. With regard to the sensor elements 181 to 184, the magnetic elements 141 to 144 can be arranged perpendicular thereto, i.e. along a z-direction arranged perpendicular to the x / y-plane. In an arrangement according to the microsystem 30, the permanent magnetic device 18 can comprise a plurality of at least one, e.g. four permanent magnetic elements 141 to 144, for generating a magnetic field associated with the respective permanent magnetic element 141 to 144. The sensor device 18 can comprise a corresponding number of sensor elements 181 to 184. Exemplarily, exactly one sensor element 181 to 184 can be explicitly associated with each permanent magnetic element 141 to 144. In Figure 3a In an example, this is done by a relative arrangement of the permanent magnets 14 i and the sensor elements 18 i with i = 1, 2, 3, 4. This allows arranging a plurality of permanent magnetic elements 14 in a mirror-symmetrical manner to the sensor elements 18 in a rest position of the microsystem 30, wherein a plane parallel to the x / y-plane is the mirror plane.

[0052] Exemplarily, the permanent magnets 141 -144 are integrated in the material or structure of the support element 121, which can exemplarily be obtained by forming a cavity in the support element 121 filled with magnetic particles and subsequently solidifying by a coating process. By subsequently planarizing one or more surfaces, a uniform surface structure can be obtained. Even without planarization, one or more permanent magnets 141 -144, i.e. magnetic elements, can be structurally integrated in the support element 121.

[0053] The sensor device 18 can comprise one or more sensor elements 181 -184, each sensor element being configured to provide a measurement signal. Exemplarily, the sensor elements 181 -184 can be implemented as Hall elements for detecting a spatial magnetic field component, or as a Hall sensor for detecting several spatial components.

[0054] Exemplarily, one sensor element 181-184 can be associated with a corresponding permanent magnet 141-144. For example, in a rest position of the microsystem 30, the respective permanent magnet 141-144 can comprise a reference position with respect to the associated sensor element 181-184, e.g. arranged to be centered.

[0055] Based on a shift of the relative position between the support elements 121 and 122, the respective position of the permanent magnets 141 to 144 with respect to the sensor elements 181 to 184 can be changed, such that one or more of the sensor signals of the sensor elements 181 to 184 can change. Exemplarily, by a rotation around the x-axis, the signals of the sensor elements 181 and 182 can remain approximately constant, while by a rotation around the y-axis, e.g. the sensor signals of the sensor elements 183 and 184 can remain approximately constant. Other relative changes of the position lead to other changes or constancies of the sensor signals. Mechanical boundary conditions related to the relative position changes can also be considered herein. Exemplarily, the permanent magnets 141 to 144 can be arranged such that a change of the mechanically allowable or provided relative movement can be detected. For example, if from the end position only a movement in one direction is possible, it can already be sufficient to arrange a single permanent magnet. If a movement along one axis but in two directions is possible, it can lead to an ambiguous measurement signal when using only one permanent magnet, which can be corrected by arranging a second permanent magnet and / or a second sensor element. Additional permanent magnets and / or sensor elements can cover additional directions. i (i = 1,..., n, n > 1) can exemplarily be arranged such that a change of the mechanically allowable or provided relative movement can be detected. For example, if from the end position only a movement in one direction is possible, it can already be sufficient to arrange a single permanent magnet. If a movement along one axis but in two directions is possible, it can lead to an ambiguous measurement signal when using only one permanent magnet, which can be corrected by arranging a second permanent magnet and / or a second sensor element. Additional permanent magnets and / or sensor elements can cover additional directions.

[0056] Figure 3b A schematic side cross-sectional view of a portion of a microsystem 30' according to an embodiment is shown. When compared to the microsystem 30, the support element 121 is formed slightly modified, e.g. such that along a radial direction (as negative x-direction) when starting from the symmetry axis 26, the magnetic element or permanent magnet 141 can differ from the permanent magnet 142. For example, the permanent magnet 141 can be arranged closer to the symmetry axis 26 than the permanent magnet 142. The permanent magnets 141 and 142 can be arranged such that a change of the mechanically allowable or provided relative movement can be detected. For example, if from the end position only a movement in one direction is possible, it can already be sufficient to arrange a single permanent magnet. If a movement along one axis but in two directions is possible, it can lead to an ambiguous measurement signal when using only one permanent magnet, which can be corrected by arranging a second permanent magnet and / or a second sensor element. Additional permanent magnets and / or sensor elements can cover additional directions. Figure 3aThe magnetic elements or permanent magnets can form an outer edge of the support element 121, which is surrounded by an outer edge 28. The outer edge 28 can comprise a support material or substrate of the support element 121. Exemplarily, such a structure can be obtained when the cavities for filling with magnetic particles are kept around the edge region 28 and are, for example, not yet exposed by an etching process or the like, or when the cavities are not placed at the terminals or edges of the support element 121. While this can reduce the maximum possible distance between two adjacent or opposite permanent magnets, this allows for advantages in terms of manufacturing, for example, because the material of the outer edge 28 is easier to process than the permanent magnets 141. The dimension 28r of the outer edge 28 along the x-direction may, for example, comprise any value as required, with embodiments providing a maximum value of 100 pm, 75 pm or 50 pm. The dimension 141r or dimension a of the permanent magnets 141 along the radial direction x can comprise any value. Exemplarily, the value a is realized to comprise a value of at least 20 pm and at most 2000 pm, at least 100 pm and at most 1500 pm, or at least 500 pm and at most 1000 pm, like 750 pm. This means that the permanent magnet arrangement can comprise at least one permanent magnetic element, wherein the permanent magnetic element can comprise a first translational dimension along x and a second translational dimension, for example y, perpendicular to the thickness direction z. The first translational dimension and / or the second translational dimension can comprise a value of at least 20 pm and at most 2000 pm.

[0057] The distance 32 between the axis of symmetry 26 and the outer edge of the permanent magnet 141 facing the axis of symmetry 26 can further comprise any value, for example, which can depend on the application of the microsystem. Exemplarily, the distance 32 comprises a value of at least 50 pm and at most 5 mm, at least 100 pm and at most 3 mm, or at least 200 pm and at most 1 mm, for example 450 pm. In case of a symmetric implementation of the support element 121, a double value of the distance 32 can describe the distance or gap between two opposite permanent magnets, for example the permanent magnets 141 and 142 of the microsystem 30.

[0058] The distance 32 and the dimension a here can be chosen such that the distance between the permanent magnetic elements is chosen such that the detection of the magnetic field of a permanent magnetic element at the position of a sensor element associated therewith is at most insignificantly influenced by the magnetic field of an adjacent permanent magnetic element. For example, an insignificant influence here can be understood such that the magnetic field of a permanent magnetic element at the position of a sensor element associated with another permanent magnetic element is at most 10%, at most 5% or at most 2% compared to the amplitude of the magnetic field of the other permanent magnetic element. This means that the magnetic field amplitude of the permanent magnetic element 141 at the position of the sensor element 182, 183 or 184 of the microsystem 30 is, for example, at most 10%, at most 5% or at most 2%. This can be accomplished by adjusting the distance b accordingly, which exemplarily relates to the center of the main side surface of the permanent magnet.

[0059] In the arrangement of the microsystem 30 shown, the distance 32 to the symmetry axis and the double distance to the opposite permanent magnetic element is for example larger than the distance to the directly adjacent permanent magnetic elements 143 and 144. The distances to the opposite and directly adjacent permanent magnets 142, 143 and 144 can here be chosen such that each of the permanent magnets 141 to 144 comprises a distance to any other permanent magnet, i.e. in any pair, the distance is at least 50 pm, at least 70 pm or at least 100 pm. Alternatively or additionally, the distance can be at least twice the lateral dimension of the permanent magnet and the other permanent magnet used to form a pair along the respective connection direction. The connection direction is for example arranged along the x-direction between the permanent magnets 141 and 142, along the y-direction between the permanent magnets 143 and 144 and along a diagonal direction between the permanent magnets 141 and 143 or 141 and 144. Thus, the distance can exemplarily correspond to twice the value a.

[0060] The sensor element 181 can comprise an extension or dimension 181r along the radial direction x which can be smaller than the dimension a, with other embodiments being possible. Exemplarily, the dimension 181r comprises a value of at least 1 pm and at most 300 pm, at most 200 pm or at most 170 pm, for example like 150 pm. While some embodiments provide a dimension of at least 20 pm, the dimension can also be below 20 pm. Exemplarily, such small magnets can be used individually or in pluralities or large numbers, for example by arranging many sensor elements in an array. Such an array can be regarded as a composite or group of several magnets or as a single combined magnetic element.

[0061] The permanent magnet 141 can comprise a thickness or length, i.e. a dimension along a direction perpendicular to the axial direction z, which is referred to as thickness 34 and can exemplarily comprise a value of at least 50 pm and at most 1000 pm, at least 100 pm and at most 700 pm or at least 200 pm and at most 500 pm, for example like 300 pm.

[0062] In the rest position of the microsystem 30 or 30', the distance 36 between the mutually facing surfaces of the permanent magnet 141 and the sensor element 181 can for example comprise a value of at most 2000 pm, at most 800 pm or at most 600 pm and is adjusted for the intended or tolerable movement of the support element 121 relative to the support element 122. This means that a design can be considered which takes into account the amplitude of the movement to be monitored relative to the relative position. A minimum distance can also apply to this movement and for example be at least 10 pm, at least 70 pm or at least 100 pm. This means that in the rest position of the microsystem, the support elements 121 and 122 can comprise a distance 36 of at least 10 pm and at most 2000 pm.

[0063] Adjacent permanent magnetic elements (e.g. 141 and 143 or 141 and 144) can comprise mutually different magnetic field directions. Exemplarily, the north poles of mutually adjacent permanent magnets can face each other, or alternatively, the south poles do so.

[0064] In other words, Figure 3a An exemplary arrangement comprising a movable spring suspended platform, e.g. made of silicon, with four integrated micro magnets and four Hall sensors located underneath and fixed to the ground is schematically shown. In Figure 3b a cross sectional view important dimensions are indicated. The platform in this exemplary arrangement can comprise a diameter of 2000 pm and a height of 300 pm, i.e. based on symmetry, the sum of distances 28r, 141r and 32 can be 1000 pm, while dimension 34 can be 300 pm. A possible square shaped magnet can have an edge length a of e.g. 500 pm at its corners, a center to center distance b of e.g. 1400 pm. The magnet extends over the entire thickness of the platform. A Si edge of 50 pm width remains along the platform perimeter. This Si edge is not shown in Figure 4a The active area of a Hall sensor can be e.g. 150 pm x 150 pm and is exemplarily located on an axis centered on the respective magnet. This axis can be arranged e.g. perpendicular to the plane of movement. Thus, movement e.g. in the x / y plane can be used to realize a corresponding axis along or parallel to the z direction as shown in Figure 3a Thus, Figure 3a and Figure 3b A schematic view of an arrangement comprising a spring suspended Si platform with four integrated micro magnets and four Hall sensors located underneath and fixed to the ground is shown, wherein Figure 3b a cross section of the platform, possibly drawn to scale, is shown.

[0065] Figure 4a and Figure 4b The influence of a magnet (e.g. permanent magnets 141 and 142 of Figure 3a ) on a single Hall sensor (e.g. sensor element 181) is shown. Distance 36 is exemplarily 100 pm. Magnet 141 can generate a strong magnetic field reflecting its geometry, the maximum of which almost completely covers Hall sensor 181. However, as shown in Figure 4b the crosstalk of magnet 142 on Hall sensor 181 is small. As shown in Figure 5a and Figure 5b a distance 36 of 300 pm also maintains this state. In contrast, Figure 4a The strength of the magnetic field 381 of permanent magnet 141 at the location of sensor element 181 is shown in a schematic top view. Figure 4b The strength of the magnetic field 381 of permanent magnet 141 at the location of sensor element 181 is shown in a schematic top view. Figure 4aThe same perspective view shows the strength of the magnetic field 382 of the permanent magnet 142, wherein it is apparent that this magnetic field does not affect or at most affects the measurement of the sensor element 181 to a non-significant extent.

[0066] Figure 5a and Figure 5b shows a diagram corresponding to Figure 4a and Figure 4b with the distance 36 increased to 300 pm. The propagation of the magnetic fields 381 and 382 can include a larger area, but based on the distance between the permanent magnets 141 and 142 is still so small that the measurement of the sensor element 181 is not affected or only to a very small extent by the adjacent permanent magnet 142.

[0067] Figure 6a and Figure 6b shows a schematic diagram of the process of the magnetic field B z exemplarily used for the sensor element 181. With an increase of the distance d sens , which can be detected in pm, for example, and which corresponds to the distance 36, the magnetic field of the permanent magnet 141 can decrease, while the magnetic field of the magnet 142 is already small and can remain constant in the zero value region.

[0068] Figure 6b shows the derivative of the curve of Figure 6a , whereby it is also apparent that the measured value of the magnetic field of the permanent magnet 142 at the position of the Hall sensor 181 is low.

[0069] In other words, Figure 6a represents the dependence of the magnetic flux density B z on the distance d sens between the sensor plane and the underside of the magnet for a travel distance of 900 pm, wherein d sens = 100 pm can represent the rest position of the microsystem. In this arrangement, the magnetic field B z generated by the permanent magnet 141 will always remain above 3 mT. At the same time, the magnetic field of the permanent magnet 142 (cross-talk) will always remain below 5% of the magnetic field of the permanent magnet 141 in terms of amplitude at equal distance. For magnetic position detection, in particular the magnetic field change depending on the position change to be detected is decisive or influential. The magnetic field absolute value at this position exemplarily decides on the detectability only by the selected magnetic field sensor and on the susceptibility only towards stray fields from the environment. For the example shown here, Figure 6b shows the change in the magnetic field when moving in the z direction, which corresponds to the derivative of the curve shown in Figure 6a . Even with a distance d sens of 400 pm (i.e. a travel distance of 300 pm), a sensitivity of better than 0.1 mT / pm can be expected.

[0070] Figure 7a It shows that the sens Schematic diagram of the magnetic field obtained at. The different curves 421 to 424 are associated with different edge lengths of the exemplary square permanent magnets 141 to 144. Curve 421 is associated with an edge length of 200 μm, curve 422 is associated with an edge length of 300 μm, curve 423 is associated with an edge length of 4 μm, and curve 424 is associated with an edge length of 500 μm. Figure 7b As shown in , which shows an exemplary schematic top view of a support element 121 , the distance b of exemplarily 1400 μm can remain unchanged, wherein a smaller dimension can be equivalent to an enlargement of the edge 28 r and / or a reduction of the overall diameter 44 , which can be exemplarily 2000 μm.

[0071] In other words, Figure 7a shows the magnetic flux density B z right Figure 7a d of the middle magnet sens and the dependence of the edge length a, while Figure 7b is based on Figure 3a and Figure 3b A top view of a platform is shown to illustrate how the magnets can be scaled. Here the thickness of the magnets and the center-to-center distance b of the magnets can be kept constant, and the thickness is 300 μm and the distance b is 1400 μm, for example. Figure 7a Shown is B z How the process depends on the size of the magnets. The magnets here are scaled in the center so that the distance b between the opposing magnets (1400 μm) and according to Figure 3a and Figure 3b The outer dimensions of the platform (2000 μm diameter) remain constant, as Figure 7b As shown in .

[0072] Figure 8a A schematic diagram showing the signal change process, namely B z The derivative of λB z , which is independent of the magnet size and provides an overview of the most important simulation results. In the case of smaller travel distances, i.e. d sens >100μm, smaller magnets are advantageous because the magnetic field here decreases over a shorter distance, so higher sensitivity can be achieved. In addition, crosstalk is reduced when using smaller magnets, such as Figure 8bThe sensitivity becomes more and more nonlinear with decreasing magnet size, however. Alternatively, the distance b between the magnets can be reduced with decreasing edge length a. This means that micro magnets with an edge length between 20 pm and 2000 pm are preferred, and micro magnets with an edge length between 500 pm and 1000 pm are preferred.

[0073] In Figure 8a the curve 461 shows the results for an edge length a = 200 pm, the curve 462 shows the results for an edge length a = 300 pm, the curve 463 shows the results for an edge length a = 400 pm, and the curve 464 shows the results for a = 500 pm. The curves show the course of the signal change, i.e. the derivative of B z , which depends on d sens and Figure 8a the edge length a of the magnets in Figure 8b a summary of the most important simulation results in

[0074] It has been shown that complex position changes of a movable MEMS structure can be monitored by using a magnetic position detection with a travel range that is at least one order of magnitude larger and has a constant spatial requirement compared to a capacitive or piezoresistive position detection. Even a simple implementation based on two pairs of micro magnets and sensors allows to detect vertical displacements and tilts, i.e. lateral displacements and twists in the plane. As already described in connection with Figure 3a and Figure 3b by using further pairs of micro magnetic sensors, similarly any three-dimensional position changes can be monitored. In Figure 4a , Figure 4b , Figure 5a , Figure 5b , Figure 6a , Figure 6b , Figure 7a , Figure 7b , Figure 8a and Figure 8b the results shown in, it is assumed that the magnetization of the integrated magnets is 450 mT, which can be used using the sintered NdFeB powder described. Alternatively or additionally, other hard magnetic materials can also be used. These include, for example, SmCo, PtCo, AlNiCo, CoFeNi, FeCrCo and different hard ferrites, as well as combinations thereof. In comparison to optical position detection, the described magnetic position detection is cheaper, less sensitive to contamination and allows a comparably high accuracy.

[0075] Figure 9aA schematic side cross-sectional view of a microsystem 90 according to an embodiment is shown, wherein the support element 121 is exemplarily arranged movable with respect to the support element 122 by movement parallel to the z-axis and / or by rotation around the y-axis. A plurality, e.g. two, permanent magnets 141 and 142 are arranged mirror-symmetrically with respect to a plane 48 arranged parallel to the x / y-plane with respect to the sensor elements 181 and 182.

[0076] While movement 521 parallel to the z-axis can result in equal changes of the measured values in the sensor elements 181 and 182, movement 522 aligned to rotation around the y-axis can result in opposite changes of the measured values. This means that the support element 121 can be relatively displaced in translational manner along at least one axis and / or tilted with respect to the support element 122.

[0077] Figure 9b A schematic side cross-sectional view of a microsystem 90 is shown in a configuration wherein the support element 121 is arranged as Figure 9a The discussion of Figure 9a is implemented for movement 523 parallel to the x-axis and / or for movement 524 as rotation around an axis parallel to the z-axis. Both movements 523 and 524 can result in equal changes of the measured values in the sensor elements 181 and 182, at least in terms of the measured amplitude.

[0078] In other words, Figure 9a and Figure 9b A schematic view of a possible arrangement for detecting vertical displacements and tilts in Figure 9a and lateral displacements and tilts in a plane in Figure 9b is shown using two pairs of micro magnetic sensors 141 / 181 and 142 / 182.

[0079] Figure 10a A schematic side cross-sectional view of a microsystem 100 according to an embodiment is shown, wherein the permanent magnet arrangement exemplarily comprises a single permanent magnet 141, while the sensor arrangement comprises a different number of sensor elements 181 and 182, respectively. The permanent magnet arrangement and / or the sensor arrangement can comprise a larger number of elements. In Figure 10aIn an embodiment of the sensor device 18, the sensor elements 181 and possibly the additional sensor elements 182 are associated with the permanent magnet element 141. This means that the sensor elements 181 and 182 are arranged spatially adjacent to the permanent magnet 141, preferably such that in case of a movement of the support elements 121 and 122 relative to each other, a measurement signal of the marker can be determined in both sensor elements 181 and 182. The sensor device 18 can comprise a computing device 54, e.g. an application specific integrated circuit (ASIC), a microcontroller, a processor, etc., which is configured to evaluate the sensor elements 181 and 182 differentially, such that the sensor signal 22 is based on a differential evaluation of the magnetic field of the permanent magnet 141 measured by using at least the sensor values 181 and 182.

[0080] This means that the sensor device 18 exemplarily comprises at least one sensor element and the evaluation circuit 54, which together form at least part of an application specific integrated circuit (ASIC).

[0081] As described in connection with the microsystem 30 or 90, the permanent magnet device and the sensor device can be arranged in different planes 481 and 482.

[0082] Figure 10b A schematic side sectional view of a modified microsystem 100' compared to the microsystem 100 is shown. The support element 122 here is shaped to provide a recess or cavity 48, which can alternatively also be referred to as a height adjacent to the support element 121. Thereby a height for the sensor elements 181 and 182 can be provided, such that the sensor device 18 or the sensor elements 181 and 182 and the permanent magnet device, in particular the permanent magnet 141, can be arranged in a common plane 48. Both sensor elements 181 and 182 can be associated with the permanent magnet 141.

[0083] According to a further embodiment, the microsystem comprises a permanent magnet device comprising at least a first permanent magnet element for generating a first magnetic field associated with the first permanent magnet element and a second permanent magnet element for generating a second magnetic field associated with the second permanent magnet element. The sensor device comprises a sensor element associated with both the first permanent magnet element and the second permanent magnet element and configured to detect an overlap of the first magnetic field and the second magnetic field. This means that several magnetic fields can be detected using a common sensor element compared to detecting a single magnetic field using several sensor elements.

[0084] These implementation manners can be combined as desired, such that different permanent magnet elements can be associated with a single sensor element Figure 3a , with several sensor elements Figure 10a and Figure 10b with other permanent magnet elements detected by several sensor elements.

[0085] According to embodiments, the sensor device comprises at least one sensor element. Each sensor element of the sensor device is configured to provide a measurement signal associated with the sensor element, like an output signal of a Hall sensor. The sensor device can be configured to at least partially correct for disturbing influences on the sensor elements.

[0086] In other words, the micro-magnets and the sensors do not necessarily have to be used in pairs. Figure 10a and Figure 10b Two further implementations are shown, in which both sensors 181 and 182 are associated with the micro-magnet 141. This allows to evaluate a differential signal. This in turn allows for a higher precision and eliminates error sources.

[0087] Figure 10a and Figure 10b A schematic diagram of a possible arrangement for detecting lateral displacements is shown, in which both sensors 181 and 182 are associated with the micro-magnet 141 to allow a differential measurement. In an arrangement according to Figure 10a The micro-magnet can be magnetized perpendicular to the plane, i.e. along the z-direction, in an arrangement according to Figure 10b In an arrangement according to

[0088] The micro-magnet can be magnetized perpendicular to the plane and within the plane, depending on the arrangement. A relative magnetization of the micro-magnets within the arrangement is also possible. All known magnetic field sensors, like Hall sensors, AMR (anisotropic magnetoresistive) sensors, GMR (giant magnetoresistive) sensors or MAGFETs (magnetic transistors) can be used for detection. Depending on the arrangement, the measurement purpose and the sensor, the measurement can be performed both within the plane and perpendicular to the plane.

[0089] Figure 11 A schematic side sectional view of a microsystem 110 according to an embodiment for correcting disturbing influences depending on the orientation is shown. The microsystem 110 is exemplarily a modification of the microsystem 100 and is extended by a reference sensor element 183 of the sensor device. The reference sensor element 183 is configured to detect a reference magnetic field and to provide a reference signal 62. The sensor device is configured to use the reference signal 62 to adjust the measurement signal 641 of the sensor element 181 and / or the measurement signal 642 of the sensor element 182 or the sensor signal 22 or a combination thereof to correct for disturbing influences that can at least partially influence the sensor elements 181 and / or 182. The sensor element 183 can exemplarily be arranged outside the magnetic fields of the permanent magnets 141 and 142. The reference magnetic field can exemplarily be a surrounding magnetic field of the microsystem, i.e. an environmental influence.

[0090] In other words, Figure 11An arrangement is shown which compensates for drift effects or improves accuracy based on the use of one or more reference sensors on the support element.

[0091] Figure 12 A schematic side sectional view of a microsystem 120 according to an embodiment is shown. When compared to the microsystem 110, it comprises a reference magnetic source 66. Its reference magnetic field overlaps with the ambient magnetic field at the position of the reference sensor, so that the combined magnetic field can be detected by the reference sensor. Preferably, the reference magnetic field is implemented to comprise, e.g., the major part of the measured magnetic field, e.g., at least 50%, at least 70% or at least 90%, in regular operation, i.e., in the presence of the normal earth magnetic field.

[0092] The reference magnetic field 66 can exemplarily be part of the sensor device and be configured to generate a reference magnetic field which is detected by the reference sensor element 183. This exemplarily allows to detect the reference magnetic field 66 as an artificially generated magnetic field in addition or alternatively to detecting environmental influences. Exemplarily, the reference magnet 66 can be formed similar or identical to the permanent magnets 141 and 142, so that a reference signal 62 can be used to detect a degradation or aging of the fixed reference magnet 66, which can be considered for the signal evaluation of the measurement signals 641 and 642. It is advantageous to fix the reference magnetic source 66 and the reference sensor element 183 to each other with respect to the relative position to obtain reliable measurement results.

[0093] The microsystem 110 and the microsystem 120 can be implemented such that the reference signal 62 is completely or partially unaffected by changes of the relative position between the support elements 121 and 122. Thus, the reference signal 62 is substantially unaffected, e.g., if it is subject to a change of at most 10%, at most 5% or at most 2% when the relative position between the support elements 121 and 122 is changed.

[0094] A potentially important basic requirement for each detection method is to be maximally independent from environmental influences. In addition to manufacturing tolerances and inherent drift effects, environmental temperature and / or electromagnetic stray fields can cause disturbances, e.g., they can significantly influence or destroy the sensor signal. By integrating additional reference sensors and / or reference micro magnets on the support element, such influences can be minimized. In the implementation according to Figure 11 In the implementation according to Figure 12 In the structure according to, a sensor-micro magnet reference pair 66 / 183 is used which is spaced apart from the movable microstructure. The advantage here is that drift and change effects of the micro magnets can be compensated. The dimensions of the micro magnets used for the reference measurement and detection can be different, but are not excluded to be identical.

[0095] In other words, Figure 12 An arrangement is shown which compensates for drift effects or improves accuracy based on using one or more sensor-micro-magnet reference pairs on the support elements.

[0096] Figure 13 A schematic flow chart of a method 1300 according to an embodiment is shown. Step 1310 comprises mechanically fixedly connecting a magnetic device configured to generate a magnetic field to a first support element. Step 1320 comprises mechanically fixedly connecting a sensor device configured to detect the magnetic field and to provide a sensor signal based on the magnetic field to a second support element. Step 1330 comprises arranging the first support element and the second support element such that a relative position of the first support element and the second support element with respect to each other is variable. The method is performed such that the sensor signal is indicative of the relative position of the support elements with respect to each other. Hence, the order of steps 1310, 1320 and 1330 can be chosen as desired. In the last mentioned step, it can be advantageous to perform the arranging of the support elements with respect to each other, for example by exposing or releasing or etching. This does not exclude subsequent steps. Prior to this, the magnetic device can be connected to the first support element and the sensor device can be connected to the second support element, since they are independent from each other due to being present on two different support substrates. Alternatively, the first support element can be processed on the second support element, for example by surface micromachining, and only thereafter the magnets in the first support element are realized. Releasing the first support element can be performed by etching from a sacrificial layer. One or more of the steps can be performed in a common processing step.

[0097] Hence, the method can be performed such that the permanent magnetic device is connected, comprising the steps of creating a recess in a region of the support element 121, filling a plurality of magnetic or magnetizable microparticles into the recess, and solidifying the plurality of magnetic or magnetizable microparticles by atomic layer deposition. Optionally, a magnetization of the magnetizable microparticles can be performed thereafter.

[0098] The number of micro-magnets and / or sensor elements in the aforementioned embodiments is only chosen exemplarily. Any other number of permanent magnetic elements and / or sensor elements and / or reference magnetic sources and / or reference sensor elements can be chosen.

[0099] The shown embodiments allow monitoring a much larger travel distance in a minimum of space when compared to capacitive and piezo-resistive position detection. A complex trajectory can be monitored using one and the same measurement arrangement. The movable microstructure does not require special electrical connections, the magnetic position detection can work in a contactless fashion and is separated from the drive. No additional forces should be applied. The described powder-based micro-magnets can be easily integrated into the microstructure. By using reference elements integrated on the same MEMS device, measurement errors caused paradigmatically by temperature or electromagnetic stray field variations can be compensated.

[0100] Embodiments can be used, among others, for magnetic position detection for MEMS scanners or micro mirrors, for MEMS aperture plates with microlenses and other optical elements, for movable microstructures with radiation sources and detectors, for movable structures in MEMS devices for producing, regulating or monitoring fluidic currents (pumps, valves, mass flux sensors, flow regulators and / or movable microstructures located in a packaging volume or system).

[0101] Possible embodiments can also be described as follows:

[0102] • An arrangement comprising a micromechanical structure movable relative to a rigid support element, comprising

[0103] o an arrangement of one or more micromagnets integrated in the movable micromechanical structure,

[0104] o and an arrangement of one or more magnetic field sensors on the rigid support element,

[0105] such that a change in the position or movement of the micromechanical structure in space results in a change in the output signal of the magnetic field sensors, which change is unambiguously related to such a change in the position or movement.

[0106] • The movable micromechanical structure can

[0107] o be connected to the support element with springs,

[0108] o else can be free to move.

[0109] • The movable micromechanical structure can comprise one or more preferred directions of movement or position changes. These can be predetermined by

[0110] o spring elements connecting the movable micromechanical structure to the support substrate,

[0111] o by a rotation axis around which the micromechanical structure can rotate,

[0112] o by a limiting surface along which the micromechanical structure can move. The movable micromechanical structure can rest on the surface, for example due to gravity, but can slide freely within this plane,

[0113] o by a limiting edge along which the micromechanical structure can move on a surface.

[0114] • The distance between the movable micromechanical structure and the rigid support element in the rest state is preferably between 50 pm and 2000 pm, particularly preferably between 100 pm and 500 pm.

[0115] • The edge length of the individual micromagnets is preferably between 20 pm and 2000 pm, particularly preferably between 50 pm and 1000 pm.

[0116] • The distance between the micromagnets is preferably between 50 pm and 3000 pm, particularly preferably between 100 pm and 1000 pm.

[0117] • The number and position of the micromagnets on the movable micro mechanical structure can be matched in mirror symmetry to the number and position of the magnetic field sensors on the support element. However, these arrangements can also differ in the number and position of the elements.

[0118] • The micromagnets and the magnetic field sensors can be paired oppositely. However, several magnetic field sensors can also be associated with one micromagnet, or one magnetic field sensor with several micromagnets.

[0119] • Preferably, but not exclusively, adjacent micromagnets on the movable micro mechanical structure are spaced apart from each other such that the stray field of a micromagnet does not influence any magnetic field sensor associated with other micromagnets.

[0120] • The reference magnetic field sensor is placed on the support element such that it is outside the stray field of the micromagnets on the movable micro mechanical structure.

[0121] • The reference micromagnet integrated in the support element is arranged opposite the reference magnetic field sensor. The reference micromagnet is fixed, i.e. its position relative to the reference magnetic field sensor does not change during the movement of the micro mechanical structure.

[0122] • Any magnetic field sensor can be used, such as Hall, AMR; e.g. GMR, MAGFET. In the case of an array, the sensors can be placed on the support element as individual chips. However, particularly in the case of small distances between the individual sensors, it is preferable to integrate them in an application-specific circuit (ASIC) manufactured by means of known semiconductor processes.

[0123] • The micromagnets are sintered from loose magnetic material powder in the micrometer range by means of atomic layer deposition (ALD).

[0124] While some aspects have been described in connection with a device, it is to be understood that these aspects also represent descriptions of corresponding methods, such that a block or an element of a device is also to be understood as a corresponding method step or as a feature of a corresponding method step. Similarly, aspects described in connection with or as a method step also represent descriptions of corresponding blocks or details or features of corresponding devices.

[0125] The above examples merely illustrate the principles of the application. Modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Accordingly, the application is intended to be limited only by the scope of the appended claims, and not by the particular details described here in the description and discussion of embodiments.

[0126] References

[0127] [1] X. Liu et al., "A MEMS stage for 3-axis nanopositioning", J. Micromech. Microeng. 17, 2007

[0128] [2] A. Hung et al., "An electrostatically driven 2D micro-scanning mirror with capacitive sensing for projection display", Sensors and Actuators A 222, 2015

[0129] [3] S. Lani et al., "2D MEMS scanner integrating a position feedback", MATEC, Web of Conferences 32, 01001, 2015

[0130] [4] B. Park et al., "Lorentz force based resonant MEMS magnetic-field sensor with optical readout", Sensors and Actuators A 241, 2016

[0131] [5] X. Cheng et al., "Integrated optoelectronic position sensor for scanning micro-mirrors", Sensors 18, 2018

[0132] [6] Operating instructions SCDplus From: 06.11.2009 Firmware v7.08

[0133] [7] UNI LEEDS Wang, Design methodology for magnetic field-based soft tri-axis tactile sensors, 2017

[0134] [8] Z.-H. Xu et al., “Grooved multi-pole magnetic gratings for high-resolution positioning systems”, Japanese Journal of Applied Physics 54, 2015

[0135] [9] C. Coutier et al., “A new magnetically actuated switch for precise position detection”, Proc. IEEE Sensors Conference, Denver, Colorado, USA, 2009

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[10] M. Nakano et al., “Nd-Fe-B Film magnets with thickness above 100 pm deposited on Si substrates”, Transactions on Magnetics, Vol. 51, No. 11, 2015

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[11] E. S. Leland et al., “A MEMS AC current sensor for residential and commercial electricity end-use monitoring”, J. Micromech. Microeng, 19, 2009

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[12] N. Jackson et al., “Integration of thick-film permanent magnets for MEMS applications”, J. Microelectromech Systems, Vol. 25, No. 4, 2016

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[13] T. Lisec et al., “A Novel fabrication technique for MEMS based on agglomeration of powder by ALD”, J. Microelectromech Systems, Vol. 26, No. 5, 2017

[0140]

[14] Patent specification EP 2670880 B1, “Verfahren zum Erzeugen einer dreidimensionalen Struktur sowie dreidimensionale Struktur” (Method for producing a three- dimensional structure, and three-dimensional structure)

[0141]

[15] Disclosure DE 102016215616 A1, “Verfahren zum Herstellen einer Magneticischen Struktur” (Method for producing a magnetic structure).

Claims

1. A microsystem, comprising: a first support element (121) and a second support element (122), wherein a relative position of the first support element (121) and the second support element (122) relative to each other is variable, wherein the first support element (121) is formed as a plate element; a permanent magnet arrangement (14) mechanically fixedly connected to the first support element (121) and configured to generate a magnetic field; a sensor arrangement (18) comprising one or more sensor elements (181-184) mechanically fixedly connected to the second support element (122) and configured to detect the magnetic field and to provide a sensor signal (22) based on the magnetic field; wherein the sensor signal (22) is indicative of the relative position of the support elements (121, 122) relative to each other, wherein the permanent magnet arrangement (14) comprises at least one permanent magnet element (141) having a plurality of particles connected to each other by atomic layer deposition to form a fixed three-dimensional structure, wherein the permanent magnet arrangement (14) comprises a plurality of permanent magnet elements (141-144) arranged at a distance from each other such that a detection of the magnetic field of a permanent magnet element (141-144) at the position of a sensor element (181-184) is at most insignificantly influenced by the magnetic field of an adjacent permanent magnet element.

2. The microsystem according to claim 1, wherein the permanent magnet arrangement (14) comprises at least one permanent magnet element (141) having a plurality of particles connected to each other by a coating to form a fixed three-dimensional structure.

3. The microsystem according to claim 1, wherein the permanent magnet arrangement (14) comprises at least one permanent magnet element (141) structurally integrated in the first support element (121).

4. The microsystem according to claim 3, wherein a material of the first support element (121) comprises a semiconductor material, a glass material or a ceramic material, and the permanent magnet element (141) is arranged in a recess of the first support element (121).

5. The microsystem according to claim 1, wherein the sensor arrangement (18) comprises at least one sensor element (181) configured to provide a measurement signal (641).

6. The microsystem according to claim 1, wherein at the position of a sensor element (181), an amplitude of a magnetic field of a first permanent magnet element (141) of the plurality of permanent magnet elements is at most 10% compared to an amplitude of a magnetic field of a second permanent magnet element (142) of the plurality of permanent magnet elements.

7. The microsystem of claim 1, wherein the distance is at least 50 pm for each pair of permanent magnetic elements (141, 142; 141, 143; 141, 144) having a first permanent magnetic element and a second permanent magnetic element of the plurality of permanent magnetic elements; or is at least twice a lateral dimension a of the first or second permanent magnetic element in a direction between the first and second permanent magnetic element.

8. The microsystem of claim 1, wherein adjacent permanent magnetic elements comprise mutually different magnetic field orientations.

9. The microsystem of claim 1, wherein at least a portion of the permanent magnetic elements (141-144) are arranged in the variation of the relative position in a plane (48) with respect to sensor elements (181-184) of the sensor device.

10. The microsystem of claim 6, wherein the variation of the relative position is in a plane (48), wherein at least a portion of the permanent magnetic elements (141-144) are arranged perpendicular to the plane (48) with respect to sensor elements (181-184) of the sensor device.

11. The microsystem of claim 1, wherein the permanent magnetic device (14) comprises a plurality of permanent magnetic elements (141-144) for generating magnetic fields each associated with the permanent magnetic elements; wherein the sensor device (18) comprises a corresponding plurality of sensor elements (181-184), wherein exactly one sensor element (181-184) is unambiguously associated with each permanent magnetic element (141-144) of the plurality of permanent magnetic elements.

12. The microsystem of claim 11, wherein in a rest position of the microsystem, the permanent magnetic elements (141-144) are arranged in a mirror-symmetrical manner opposite to the sensor elements.

13. The microsystem of claim 1, wherein the sensor device (18) comprises at least one sensor element (181-184), wherein each sensor element (181-184) is configured to provide an associated measurement signal (64), the sensor device (18) is configured to at least partially correct for a disturbing influence on the at least one sensor element (18).

14. The microsystem of claim 13, wherein the sensor device (18) comprises a reference sensor element (183) configured to detect a reference magnetic field and to provide a reference signal (62), the sensor device (18) is configured to use the reference signal (62) to adjust the measurement signal (64) or the sensor signal (22) to at least partially correct for the disturbing influence.

15. The microsystem of claim 14, wherein the reference magnetic field is an ambient magnetic field of the microsystem.

16. The microsystem of claim 14, wherein the sensor device comprises a reference magnetic source (66) configured to generate the reference magnetic field.

17. The microsystem according to claim 16, wherein the relative position between the reference magnetic source (66) and the reference sensor element (183) is fixed.

18. The microsystem according to claim 14, wherein the reference signal (62) is substantially not affected by the relative position variation.

19. The microsystem according to claim 1, wherein the permanent magnetic means (14) comprises at least one permanent magnetic element (141), the permanent magnetic element (14) comprising a first translation dimension and a second translation dimension, the first translation dimension being perpendicular to the thickness direction z, the second translation dimension being a second perpendicular translation dimension, wherein the first and / or second translation dimension comprises a value of at least 20 pm and at most 2000 pm.

20. The microsystem according to claim 1, wherein in a rest position of the microsystem, the first support element (121) and the second support element (122) comprise a distance (36) of at least 10 pm and at most 2000 pm.

21. The microsystem according to claim 1, wherein the first support element (121) is relatively displaceable in a translational manner along at least one axis with respect to the second support element (122) and / or is tiltable with respect to the second support element (122).

22. The microsystem according to claim 1, wherein the sensor signal (22) unambiguously indicates the relative position of the support elements (121-124) with respect to each other.

23. The microsystem according to claim 1, wherein the sensor means (18) comprises at least one sensor element (181), the sensor element being implemented as a Hall sensor, an AMR sensor, a GMR sensor or a MAGFET.

24. The microsystem according to claim 1, wherein the sensor means (18) comprises at least one sensor element (181), and the sensor element (181) and an evaluation circuit (54) of the sensor means (18) form an application-specific integrated circuit, ASIC.

25. The microsystem according to claim 1, wherein the first support element (121) is a movable support element, and the second support element (122) comprises a substrate, such that the sensor signal (22) is indicative of a position of the movable support element with respect to the substrate.

26. The microsystem according to claim 1, wherein the first support element (121) is connected to the second support element (122) via at least one spring element (241).

27. The microsystem according to claim 26, wherein the at least one spring element (241) is pre-set for changing the relative position.

28. The microsystem according to claim 1, wherein the second support element (122) is formed as a plate element.

29. The microsystem according to claim 28, wherein the plate element is a mirror.

30. The microsystem according to claim 1, wherein a direction of variation of the relative position is based on: at least one orientation of a spring element (241) between the first support element (121) and the second support element (122); or at least one rotational axis for allowing rotation of the first support element (121) or the second support element (122); or at least one limiting surface or limiting edge along which movement of the first support element and / or the second support element is pre-determined.

31. The microsystem of claim 1, formed as a scanner, an electrical switch, an optical switch, a valve or a pump.

32. A method (1300) for producing a microsystem, comprising the steps of: providing a first support element in the form of a plate element; mechanically fixedly connecting (1310) a permanent magnetic arrangement (14) to the first support element, the permanent magnetic arrangement being configured to generate a magnetic field; mechanically fixedly connecting (1320) a sensor arrangement comprising one or more sensor elements (181-184) to a second support element, the sensor arrangement being configured to detect the magnetic field and to provide a sensor signal based on the magnetic field; arranging (1330) the first support element and the second support element such that a relative position between the first support element and the second support element is variable; such that the sensor signal is indicative of the relative position between the support elements; and wherein the permanent magnetic arrangement (14) comprises a plurality of permanent magnetic elements (141-144) arranged at a distance from each other such that detection of the magnetic field of a permanent magnetic element (141-144) at the position of a sensor element (181-184) is at most insignificantly influenced by the magnetic field of an adjacent permanent magnetic element; and wherein connecting the permanent magnetic arrangement comprises the steps of: creating a recess in a region of the first support element; filling a plurality of magnetic or magnetizable microparticles into the recess; and solidifying the plurality of magnetic or magnetizable microparticles by atomic layer deposition.

33. A microsystem, comprising: a first support element (121) and a second support element (122), wherein a relative position of the first support element (121) and the second support element (122) with respect to each other is variable; a permanent magnetic arrangement (14) mechanically fixedly connected to the first support element (121) and configured to generate a magnetic field; a sensor arrangement (18) mechanically fixedly connected to the second support element (122) and configured to detect the magnetic field and to provide a sensor signal (22) based on the magnetic field; wherein the sensor signal (22) is indicative of the relative position of the support elements (121, 122) with respect to each other, wherein the permanent magnetic arrangement (14) comprises at least one permanent magnetic element (141) having a plurality of particles connected to each other by atomic layer deposition to form a fixed three-dimensional structure, wherein the permanent magnet device (14) comprises a plurality of permanent magnet elements (141-144) for generating a magnetic field each associated with the permanent magnet element; wherein the sensor device (18) comprises a corresponding plurality of sensor elements (181-184), wherein exactly one sensor element (181-184) is explicitly associated with each permanent magnet element (141-144) of the plurality of permanent magnet elements; wherein in the rest position of the microsystem, the permanent magnet elements (141-144) are arranged in a mirror-symmetrical manner opposite to the sensor elements.

34. A microsystem, comprising: a first support element (121) and a second support element (122), wherein the relative position of the first support element (121) and the second support element (122) relative to each other is variable; a permanent magnet device (14) mechanically fixedly connected to the first support element (121) and configured to generate a magnetic field; a sensor device (18) mechanically fixedly connected to the second support element (122) and configured to detect the magnetic field and to provide a sensor signal (22) based on the magnetic field; wherein the sensor signal (22) is indicative of the relative position of the support elements (121, 122) relative to each other, wherein the permanent magnet device (14) comprises at least one permanent magnet element (141) having a plurality of particles connected to each other by atomic layer deposition to form a fixed three-dimensional structure, wherein the sensor device (18) comprises at least one sensor element (181-184), wherein each sensor element (181-184) is configured to provide an associated measurement signal (64), the sensor device (18) being configured to at least partially correct for a disturbing influence on the at least one sensor element (18); wherein the sensor device (18) comprises a reference sensor element (183) configured to detect a reference magnetic field and to provide a reference signal (62), the sensor device (18) being configured to use the reference signal (62) to adjust the measurement signal (64) or the sensor signal (22) to at least partially correct for the disturbing influence; wherein the sensor device comprises a reference magnetic source (66) configured to generate the reference magnetic field.

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