Rotational speed sensor and method for producing rotational speed sensor
By adopting a spring structure, stop and accompanying structure in the speed sensor, the problems of break stability, nonlinearity of reset force and manufacturing tolerance in the prior art are solved, and efficient and stable speed detection is achieved.
Patent Information
- Application Number
- CN202411382909.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-10-06
- Filing Date
- 2024-09-30
- Publication Date
- 2025-04-08
AI Technical Summary
Existing speed sensors have fracture stability problems, nonlinearity of reset force and manufacturing tolerances when detecting speed.
Using a spring structure, stop and accompanying structure, the winding part and frame elements are formed through section-like straight extension beam elements, which bear bending and torsional loads, avoid stretching and compression, and ensure mechanical break stability and optimization of manufacturing tolerances.
It effectively avoids nonlinearity of reset force, improves mechanical fracture stability, reduces manufacturing tolerances, and ensures efficient speed detection.
Smart Images
Figure CN119780460A_ABST
Abstract
Description
Technical Field
[0001] The invention is based on a rotational speed sensor having a substrate and a sensor element, and on a method for producing such a rotational speed sensor. Background Art
[0002] Rotational speed sensors which detect rotational speed signals in at least one sensitive direction based on the Coriolis effect are generally known in a number of embodiments and designs. Also generally known are rotational speed sensors in which the sensor element performs torsional vibrations about the rotation axis, so that the rotational speed can be detected in at least one sensitive direction by means of the sensor element which is designed as a rotor structure. The functional principle of such rotational speed sensors provides that the sensor element or the rotor structure performs such torque vibrations about the rotation axis perpendicular to the substrate (i.e., torque vibrations about the drive axis perpendicular to the main extension plane of the substrate) and, when the rotational speed acts in one of the sensitive directions, tilts about the tilting axis (due to the angle of the Coriolis effect); such tilting of the rotor structure can be detected by electronic detection methods, such as capacitive differential detection and / or piezoelectric methods, and evaluated in conjunction with an electronic evaluation device (ASIC).
[0003] However, known rotational speed sensors of this type have disadvantages with regard to fracture stability, the need to avoid non-linearities in the restoring forces caused by drive deflections, and the influence of manufacturing tolerances. Summary of the invention
[0004] The object of the present invention is to provide a rotational speed sensor having a substrate and a sensor element which, due to the design of the rotor structure or the spring structure, either does not have the above-mentioned disadvantages or exhibits at least one improved behavior.
[0005] The rotational speed sensor according to the invention with a substrate and a sensor element has the following advantages compared to the prior art: Due to the design of the spring structure (essentially straight beam elements extending in sections, which are attached or connected to one another in such a way that the relevant beam elements each form an angle of 90°), nonlinearities of the restoring force associated with the deflection of the sensor element, in particular the drive deflection, can be avoided in a particularly advantageous manner, in that (due to the arrangement of the beam elements) the straight beam elements extending in sections are subjected to bending and / or torsional loads to a greater extent than to tensile and / or compressive loads. Advantageously, thus, possible interference modes when detecting the rotational speed are shifted into the high-frequency range and the rotational speed can be detected efficiently in at least one sensitive direction.
[0006] Furthermore, a high mechanical fracture stability is ensured by means of the spring structure and the outer sensor frame used as a seismic mass, since the stresses occurring both in the case of rotational drive deflections and in the case of translational deflections, in particular due to overload deflections or mechanical shocks (overloads caused by linear acceleration and / or rotational acceleration), are kept to a minimum or below a critical stress value. Furthermore, the structuring of the sensor frame and the spring structure allows a very efficient reduction of manufacturing tolerances during the production process, since, due to the structuring, in particular the structuring of the spring structure, due to the segmented straight beam elements or due to the stops and accompanying structures, favorable etching conditions can be utilized or ensured. This results in particular in advantages with regard to dimensional manufacturing tolerances or manufacturing errors and with regard to the spring stiffness of the corresponding segmented straight beam elements.
[0007] Advantageous embodiments and developments of the invention can be gathered from the description and the drawings.
[0008] According to an advantageous embodiment of the invention, the rotational speed sensor comprises at least one stop and an accompanying structure in the sensor frame, wherein the stop and the accompanying structure are provided for achieving a largely uniform etching environment in the sensor frame. Due to the at least one stop and the accompanying structure, in particular due to the stop or the stop element, it is advantageously possible to increase the mechanical fracture stability, in particular with regard to the stresses that occur, in the case of mechanical shocks (overloads caused by linear acceleration and / or rotational acceleration), or to keep the stresses acting on the spring structure below a critical value despite such conditions. Furthermore, a uniform etching environment or a uniform etching environment is advantageously provided in the sensor frame by the stop and the accompanying structure. In particular, such etching conditions are also provided around the spring structure and thus the rigidity and width or the dimensions of the beam element extending substantially in sections in a straight manner fluctuate less, in particular taking into account the existing manufacturing tolerances.
[0009] According to an advantageous embodiment of the invention, the sectionally straight beam elements of the spring structure are arranged in such a way that the spring structure forms or has a meander and / or the spring structure has a frame element or a plurality of frame elements and / or the spring structure has a torsion element, in particular a torsion spring. In particular, since this arrangement can effectively avoid stretching and / or compression of the spring structure or the sectionally straight beam elements, the spring structure or the beam elements are primarily subjected to bending and / or torsion loads. As a result, nonlinearities in the reset force can be minimized very efficiently during deflection of the sensor element and overload deflections can be effectively counteracted.
[0010] According to an advantageous embodiment of the invention, the stop and the accompanying structure have a stop element. In particular, the stop element can ensure that a certain maximum possible deflection is not exceeded, so that stresses triggered by mechanical shocks (in the case of overloads caused by linear acceleration and rotational acceleration, for example) can be effectively limited or kept below a critical stress value.
[0011] According to an advantageous embodiment of the invention, the spring structure has a notch, in particular in the central region. With such a notch, limitations due to layout rules or lateral etching rules (during production) can be effectively avoided, so that in particular better production tolerances can be achieved.
[0012] According to an advantageous embodiment of the invention, the base suspension of the spring structure is realized by at least one anchor bolt, in particular by at least two anchor bolts, preferably by at least four anchor bolts. The base suspension of the spring structure is thus advantageously anchored to the base and very advantageously supplements not only the spring structure but also the rotor structure.
[0013] A further subject matter of the invention is a method for producing a rotational rate sensor having a substrate and a sensor element.
[0014] The method for manufacturing a rotation speed sensor with a substrate and a sensor element according to the invention proves to be advantageous compared to the prior art in that the favorable etching environment determined by the (pursued) structuralization of the sensor frame and the spring structure allows extremely favorable minimization of processing fluctuations or manufacturing tolerances. In particular, the arrangement of the (pursued) straight beam elements extending in sections contributes to the favorable etching environment and thus allows to suppress processing fluctuations, especially those related to the size of the beam elements and their spring stiffness, to a large extent. In addition, due to the arrangement of the straight beam elements extending in sections, the spring structure is basically only subjected to bending and / or torsional loads, rather than tension and / or compression. Therefore, possible interference modes in the detection of the rotation speed acting in particular in at least one direction can be extremely advantageously suppressed or offset into the high-frequency region and efficient and effective rotation speed detection can be ensured. In addition, nonlinearities related to the reset force can be avoided or suppressed during deflection, especially in terms of the drive deflection of the sensor element. This avoidance of overload deflection ensures high mechanical fracture stability for the maximum occurring stresses during full deflection or tipping (i.e., as far as is permitted due to the structuralization), especially during mechanical impacts.
[0015] According to an advantageous embodiment of the invention, the rotational speed sensor is designed in such a way that the sensor element comprises at least one stop and an accompanying structure within the sensor frame, wherein the stop and the accompanying structure are designed in such a way that a largely homogeneous etching environment is achieved within the sensor frame during the production of the rotational speed sensor, in particular the spring structure.
[0016] The advantages and embodiments described in conjunction with the specific embodiments of the rotational rate sensor according to the invention having a substrate and a sensor element can be used for the method for producing a rotational rate sensor having a substrate and a sensor element. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Exemplary embodiments of the invention are depicted in the drawings and are explained in more detail in the following description.
[0018] Figure 1 A schematic diagram shows a part of a rotational speed sensor according to an embodiment of the present invention, namely a sensor element according to the described embodiment as well as (associated) stops and accompanying structures, wherein the sensor element constructed as a rotor structure comprises an outer sensor frame as a seismic mass, a substrate suspension manufacturing and a spring structure located between them.
[0019] Figure 2 Schematically and enlargedly shown Figure 1 Detail of a sensor element is shown in FIG. , namely in particular the spring structure.
[0020] Figure 3 A) to 3C) each show in schematic diagram further exemplary embodiments for realizing a sensor element of a rotational rate sensor according to the invention.
[0021] Figure 4 A schematic diagram shows a portion of a rotational speed sensor according to another embodiment of the present invention, namely a sensor element according to the described embodiment as well as (associated) stops and accompanying structures, wherein the sensor element, which is constructed as a rotor structure, comprises an external sensor frame as a seismic mass, a substrate suspension and a spring structure located between them.
[0022] Figure 5 A schematic diagram shows a portion of a rotational speed sensor according to another embodiment of the present invention, namely a sensor element according to the described embodiment as well as (associated) stops and accompanying structures, wherein the sensor element, which is constructed as a rotor structure, comprises an external sensor frame as a seismic mass, a substrate suspension and a spring structure located between them. DETAILED DESCRIPTION
[0023] Figure 1A schematic diagram shows a part of a rotational speed sensor according to an embodiment of the invention, namely a sensor element designed as a rotor structure, which has an outer sensor frame 30 as a seismic mass, a substrate suspension 10 and a spring structure 20 located between them. The substrate (not explicitly described here) extends in a main extension plane 100, which corresponds to the plane spanned by the x-axis and the y-axis (and the drawing plane). The rotor structure is attached to the substrate by means of the substrate suspension 10 (by means of anchor bolts).
[0024] Figure 1 In addition to the rotor structure, the accompanying and stop structures 50, 40 are described, which are arranged inside the sensor frame 30 but at a distance therefrom and do not carry out torsional vibrations together with the sensor frame, but are instead essentially fixed relative to the substrate. The stop and accompanying structures 40, 50 are arranged or disposed within the outer sensor frame 30, in particular at a distance not only from the outer sensor frame 30 but also from a subregion of the spring structure 20, in such a way that essentially the same or similar distances result, so that, in particular, the etching conditions are largely the same when producing or structuring the rotor structure.
[0025] For all embodiments, the sensor element or the rotor structure, in particular the sensor frame 30, is driven by means of a drive device (not shown in any of the figures) to torsionally vibrate (in a plane) about a drive axis (parallel to the z-axis) and in the process deflects a drive deflection (in a plane) in the sense of this torsion vibration. By means of a detection device (also not shown in any of the figures), at least one rotational speed (or rotational speed component) acting in a sensitive direction (x-axis or y-axis) can be detected by means of a tilting of the sensor element or the rotor structure (out of a plane) about a tilting axis (parallel to the main extension plane 100). The detection is preferably carried out by means of capacitive differential detection or reading and / or by means of a piezoelectric method. The tilting axis (y-axis or x-axis) is oriented perpendicularly to the at least one rotational speed acting in the sensitive direction (x-axis or y-axis) and perpendicularly to the drive axis (z-axis). By means of the stop and accompanying structure 40, 50, overload deflections associated with the drive deflection of the sensor element can be substantially avoided in a very advantageous manner, so that the described advantages of high mechanical stability or fracture stability and advantages with respect to mechanical shocks or overloads can be achieved. Furthermore, in particular in connection with the production of the rotational speed sensor, the stop and accompanying structures 50 , 40 enable a largely uniform etching environment to be achieved, so that processing fluctuations can also be reduced, in particular in connection with etching or etching steps carried out in the outer sensor frame 30 during the production of the rotational speed sensor, i.e. in particular in connection with the substrate suspension device 10 and the spring structure 20 .
[0026] exist Figure 1In and according to all embodiments of the invention, the rotor structure comprises an outer sensor frame 30 serving as a seismic mass and a spring structure 20; the spring structure 20 is connected to a substrate (not depicted in all figures) in a central region by means of at least one substrate suspension 10, wherein the spring structure 20 is constructed between one end thereof, i.e. its attachment 25 to the substrate suspension 10, and the other end thereof, i.e. its attachment 25' to the sensor frame 30, in such a way that the spring structure 20 has (or consists of) beam elements 22 extending substantially straight in sections, and that every two beam elements 22 following one another of these beam elements are attached to or connected to one another at at least five locations 21 in such a way that every two of the beam elements 22 involved form at least a right angle (i.e. an angle of at least or including 90°). This is in accordance with the invention. Figure 1 The local area marked with a dotted line (and the enlarged area) is also Figure 2 Described in detail:
[0027] exist Figure 2 The left part also shows a piece of the base suspension device 10, to which the spring structure 20 is attached by means of its attachment portion 25; Figure 2 The right part shows a piece of the outer sensor frame 30 . Figure 2 Only described (in Figure 1 2 and present in this exemplary embodiment by way of example) a single spring structure 20 or sub-spring structure 20 of a total of two spring structures or sub-spring structures described in FIG.
[0028] according to Figure 1 The spring structure 20 (or sub-spring structure 20) of the embodiment of the present invention has a total of nine straight beam elements 22 extending in sections starting from the attachment 25 of the spring structure 20 (to the base suspension device 10), wherein in the embodiment described, in particular the second to eighth beam elements 22 form a folded frame structure with other similar beam elements arranged in a mirror-symmetrical manner. The frame structure 20 (or sub-frame structure 20) is denoted by the reference numeral 21 (in Figure 2 In the upper part of the folded frame structure shown), the locations marked in each case have an angled course in this sense (in accordance with Figure 1 and 2 In the exemplary embodiment of the present invention, the spring structure 20 has a right angle in each case): two beam elements 22 that follow one another (and each extend straight when viewed in themselves) are attached to one another or connected to one another (or are structured accordingly) at the location marked with the reference numeral 21 and each form the mentioned 90° angle. In this regard, the spring structure 20 is based on Figure 1 and 2A meander is formed (or has a meander), wherein the nine beam elements (of each path between the attachment portions 25, 25') have a 90° angle at eight locations 21 between them. Figure 1 and 2 The folded frame structure, which includes both the upper second to eighth straight beam elements 22 and the lower second to eighth straight beam elements 22 , also has a frame structure or a frame element.
[0029] It can thus be achieved very advantageously that the beam element 22 (and therefore also the spring structure 20) is subjected essentially only to bending and / or torsional loads and thus on the one hand a stretching and / or compression of the spring structure 20 or parts of the spring structure 20 is avoided, so that possible interference modes when detecting the rotational speed to be measured can be shifted to the high-frequency region and nonlinearities of the restoring forces, in particular those associated with the drive deflection, can be greatly reduced. Figure 1 (as well as Figure 2 ) embodiment, the spring structure 20 is a composite body composed of multiple single sections (beam (element) 22) and is also responsible for realizing the useful mode (driving and detection). Through the meandering part of the spring structure 20, when deflection occurs in the useful mode, the stretching (of the beam element) is avoided or the bending of the single section can make the overall movement possible to a great extent. In the case of overload in the y-direction, for example in the case of linear acceleration, the stop element (of the stop and accompanying structure 50, 40) marked with an arrow and the reference mark 40 can stop the overload deflection after a short stroke and avoid damage. This topology is particularly advantageous for situations where there is overload when there is linear acceleration in the y-direction. The accompanying structure 50 or the stop and accompanying structures 50, 40 load a uniform etching environment and are particularly conducive to reducing processing fluctuations.
[0030] Figure 3 A to 3C schematically show further alternative embodiments or implementations of the spring structure 20 according to the invention, which are also respectively (i.e. according to Figure 3 A to 3C or all embodiments or variants thereof) are arranged between the outer sensor frame 30 as a seismic mass and the substrate suspension 10. In all embodiments ( Figure 3 A to 3C) describe a base suspension 10, a spring structure 20 having at least one meander 12 in all these embodiments, and an outer sensor frame 30, which is also representative. In addition, the spring structure 20 with the meander consists of a plurality of essentially segmented straight beam elements 22 that follow one another and are attached or connected to one another at least five locations in such a way that every two of the beam elements 22 involved form an angle of at least 90°.
[0031] Figure 4 A schematic diagram shows a portion of a rotational speed sensor having a substrate and a sensor element according to another embodiment of the present invention, i.e., the sensor element according to the described embodiment as well as (associated) stops and accompanying structures 40, 50, wherein the sensor element, which is constructed as a rotor structure, comprises an external sensor frame 30 as a seismic mass, a substrate suspension device 10 and a spring structure 20 located between them.
[0032] As in the previously described embodiments, the stop and accompanying structures 40 , 50 are arranged or disposed within the outer sensor frame 30 , in particular not only relative to the outer sensor frame 30 , but also relative to a subregion of the spring frame 20 , in such a manner that essentially the same or similar distances result, so that, in particular, the etching conditions during the production or structuring of the rotor structure are largely the same.
[0033] In accordance with Figure 4 In an embodiment, the spring structure 20 is also constructed between its one end, i.e. its attachment 25 on the base suspension device 10, and its other end, i.e. its attachment 25' on the sensor frame 30, in such a way that the spring structure 20 has (or consists of) beam elements 22 extending straightly in a substantially section-like manner and that every two beam elements 22 following one another are attached to or connected to one another at at least five locations 21 in such a way that every two beam elements 22 involved form at least a right angle (i.e. an angle of at least 90°). According to Figure 4 In the embodiment of the present invention, the spring structure 20 specifically comprises four individual attachments 25 on the base suspension device 10. Starting from each of these attachments 25 on the base suspension device 10 (until the attachment 25' of the spring structure 20 on the sensor frame 30), the spring structure 20 has a total of six segmented straight-running beam elements 22. The frame structure 20 at the locations marked with the reference numeral 21 again has an angled course in this sense: two beam elements 22 that follow one another (and each extend straight when viewed in themselves) are attached to or connected to one another (or are structured accordingly) at the locations marked with the reference numeral 21 and each form the mentioned 90° angle. In this regard, according to Figure 4 The spring structure 20 forms a meander (or has a meander), wherein the six beam elements (of each path between the attachment portions 25, 25') have an angle of (at least) 90° at five locations 21 between them. Figure 4In an embodiment, every second such beam element 22 forms a (internal) frame element 23; every third such beam element 22 forms a (internal) torsion element 24; every fourth beam element 22 forms a (external) further frame element 23'; and every fifth beam element 22 forms a (external) further torsion element 24'.
[0034] Therefore, according to Figure 4 The embodiment of the spring structure 20 is applicable: firstly, by means of diagonally extending spring beams (i.e. corresponding to the (four existing) first beam elements 22), each starting from a corresponding attachment 25 on the base suspension device 10 and Figure 4 The deflection in the plane (indicated by reference numeral 22' in the figure) enables the drive deflection. In the detection mode about the x-axis, the torsion spring (further torsion element 24') is deflected first; in the detection mode about the y-axis, the torsion spring (torsion element 24) is deflected first. This distribution (or "division of tasks") between the individual elements of the spring structure 20 advantageously makes it possible to determine the frequencies of the individual useful modes by independent geometric variables. The use of frame elements 23, 23' and relatively short torsion elements 24, 24' makes it possible for parallel out-of-plane interference modes to have very high frequencies. The element 50 of the stop and accompanying structure 40, 50 enables a uniform etching environment and corresponding robustness with respect to process fluctuations, while the stop elements 41, 42 help to avoid damage in the event of overload.
[0035] Figure 5 A schematic diagram shows a portion of a rotational speed sensor according to another specific embodiment of the invention, namely a sensor element according to the described specific embodiment as well as (associated) stops and accompanying structures 40, 50, wherein the sensor element, which is again designed as a rotor structure, again comprises an outer sensor frame 30 as a seismic mass, a base suspension 10 and a spring structure 20 located therebetween. In contrast to the previous specific embodiments, according to Figure 5 The spring structure 20 of the embodiment of is realized by a substrate suspension 10 having four anchor bolts. As in the previously described embodiments, the stop and accompanying structures 40, 50 are arranged or disposed within the outer sensor frame 30, in particular both relative to the outer sensor frame 30 and relative to a subregion of the spring frame 20, at such a distance that essentially the same or similar distances are produced, so that in particular the etching conditions during the production or structuring of the rotor structure are largely the same.
[0036] In accordance with Figure 5In an embodiment, the spring structure 20 is also constructed between its one end, i.e. its attachment 25 on the base suspension device 10, and its other end, i.e. its attachment 25' on the sensor frame 30, in such a way that the spring structure 20 has (or consists of) beam elements 22 extending straightly in a substantially section-like manner and that every two beam elements 22 following one another are attached to or connected to one another at at least five locations 21 in such a way that every two beam elements 22 involved form at least a right angle (i.e. an angle of at least 90°). According to Figure 5 The spring structure 20 of the embodiment comprises specifically five individual attachments 25 on the base suspension 10. Starting from each attachment 25 on the base suspension 10, the spring structure 20 (up to its attachment 25' on the sensor frame 30) has a total of six segmented straight beam elements 22. The frame structure 20 in turn has an angled course at the locations marked with the reference numeral 21 in the sense that two beam elements 22 following one another (and each extending straight when viewed in themselves) are attached to or connected to one another (or structured accordingly) at the locations marked with the reference numeral 21 and each form the mentioned 90° angle. In this regard, according to Figure 5 The spring structure 20 also forms a meander (or has a meander), wherein the six beam elements (of each path between the attachment portions 25, 25') have a 90° angle at five locations 21 between them. Figure 5 In an embodiment, every second such beam element 22 forms a torsion element 26; every third such beam element 22 forms a first further torsion element 26'; every sixth beam element 22 forms an (external) second further torsion element 28; and every fourth and fifth beam element 22 forms a frame element 27.
[0037] Therefore, according to Figure 5 The embodiment of the spring structure 20 applies: firstly, the drive movement can be realized by the deflection of the additional torsion element 26' (or spring) and the frame structure 27; the detection movement about the x-axis can be realized mainly by the torsion of the torsion elements 26, 28 and the detection movement about the y-axis can be realized by the torsion of the torsion element 26'. The stop accompanying structures 40, 50 ensure a uniform etching environment, while the stop element 40 helps to avoid damage in the case of combined overload accelerations in the x-direction and the y-direction. The notch 29 enables advantageous properties with regard to fracture robustness; in addition, the parameter space of the spring width of the torsion elements 26, 26' can be expanded, since without the notch 29 there would be restrictions due to the lateral etching width due to layout rules.
Claims
1. A rotation speed sensor comprising a substrate and a sensor element, wherein: The substrate has a main extension plane (100), wherein the sensor element is designed as a rotor structure, which is driven by a drive device with a drive deflection to perform torsional vibrations about a drive axis (z) perpendicular to the main extension plane (100), wherein a rotation speed about at least one sensitive direction perpendicular to the drive axis can be detected by means of a detection device based on a tilting of the sensor element about a tilting axis perpendicular to the drive axis (z) and perpendicular to the at least one sensitive direction, characterized in that the rotor structure comprises an outer sensor frame (30) serving as a seismic mass and comprises a spring structure (20), and The spring structure (20) is connected to the substrate in a central region by means of at least one substrate suspension device (10), wherein the spring structure (20) has or consists of beam elements (22) extending substantially straight in sections between its attachment portion (25) on the substrate suspension device (10) and its attachment portion (25') on the sensor frame (30), wherein each two beam elements (22) following one another are attached or connected to one another at at least five locations (21) in such a way that each two beam elements (22) involved form an angle of at least 90°.
2. The speed sensor according to claim 1, characterized in that: The rotational speed sensor comprises at least one stop and accompanying structure (40, 50) inside the sensor frame (30), wherein the stop and accompanying structure (40, 50) are provided to achieve a largely homogeneous etching environment inside the sensor frame (30).
3. The rotational speed sensor according to any one of the preceding claims, characterized in that The sectionally straight beam element (22) of the spring structure (20) is arranged such that The spring structure (20) forms or has a meandering portion (12), and / or The spring structure (20) has a frame element or a plurality of frame elements (23, 23'), and / or The spring structure (20) has a torsion element (24, 24'), in particular a torsion spring.
4. The rotational speed sensor according to any one of the preceding claims, characterized in that The stop and accompanying structure (40, 50) has a stop element (41, 42).
5. The rotational speed sensor according to any one of the preceding claims, characterized in that The spring structure (20) has a recess (29), in particular in a central region.
6. The rotational speed sensor according to any one of the preceding claims, characterized in that The base suspension device (10) of the spring structure (20) can be realized with at least one anchor bolt, in particular with at least two anchor bolts, preferably with at least four anchor bolts.
7. A method for producing a rotational speed sensor having a substrate and a sensor element, wherein: The substrate has a main extension plane (100), wherein the sensor element is configured as a rotor structure, which can be driven by a drive device with a drive deflection to perform torsional vibrations about a drive axis (z) perpendicular to the main extension plane (100), wherein a rotation speed about at least one sensitive direction perpendicular to the drive axis can be detected by means of a detection device based on a tilting of the sensor element about a tilting axis perpendicular to the drive axis (z) and perpendicular to the at least one sensitive direction, characterized in that the rotor structure comprises an outer sensor frame (30) serving as a seismic mass and comprises a spring structure (20), and the spring structure (20) is centrally mounted The spring structure (20) is connected to the substrate in a region by means of at least one substrate suspension device (10), wherein, for the production of the rotational speed sensor, the spring structure (20) is designed such that the spring structure (20) has or consists of beam elements (22) extending substantially straight in sections between its attachment portion (25) on the substrate suspension device (10) and its attachment portion (25') on the sensor frame (30), wherein each two of the beam elements (22) following one another are attached or connected to one another at at least five locations (21) such that each two of the beam elements (22) involved form an angle of at least 90°.
8. The method according to claim 7, characterized in that The rotational speed sensor comprises at least one stop and an accompanying structure (40, 50) within the sensor frame (30), wherein the stop and the accompanying structure (40, 50) are designed in such a way that a largely homogeneous etching environment is achieved within the sensor frame (30) during the production of the rotational speed sensor, in particular the spring structure (20).