Microelectromechanical component, microelectromechanical part and microelectromechanical device

Abstract

The invention relates to a microelectromechanical component (1) with a substrate (2) having a substrate recess (3) bounded by a substrate frame (2a), and at least one displacement element (4) extending in the substrate recess (3), which is anchored to a first frame part (2a-I) of the substrate frame (2a) by a first fastening section (5) and is deflectable at least in part, wherein the at least one displacement element (4) has a stiffness-reducing section (7). The invention further relates to a microelectromechanical component (18) and a microelectromechanical device (19).

Description

[0001] The invention relates to a microelectromechanical component, a microelectromechanical component with such a microelectromechanical component and a microelectromechanical device with such a microelectromechanical component. State of the art

[0002] Microelectromechanical components, parts, and devices are known from the prior art. Microelectromechanical systems are also abbreviated as MEMS.

[0003] WO 2022 / 117 197 A1 relates to a MEMS device with a layer stack comprising a plurality of MEMS layers arranged along a layer sequence direction. The MEMS device includes a movable element formed in a first MEMS layer, which is arranged between a second MEMS layer and a third MEMS layer of the layer stack. Furthermore, a drive unit is provided, comprising a first drive structure mechanically rigidly connected to the movable element and a second drive structure mechanically rigidly connected to the second MEMS layer. The drive unit is configured to generate a drive force perpendicular to the layer sequence direction at the movable element, and the drive force is designed to deflect the movable element. Disclosure of the invention

[0004] According to the features of independent claim 1, a microelectromechanical device is proposed comprising a substrate which has a substrate recess bounded by a substrate frame, with at least one displacement element extending in the substrate recess, which is anchored to a first frame part of the substrate frame by a first fastening section and is deflectable at least in part, wherein the at least one displacement element has a stiffness reduction section.

[0005] A stiffness-reducing section incorporated into the displacement element allows for greater deflections of the displacement element due to the section-by-section reduction in stiffness. This enables a higher displacement performance with the microelectromechanical device. A microelectromechanical device with a displacement element featuring a stiffness-reducing section can be designed to be smaller than a device with a displacement element that does not have a stiffness-reducing section, in order to achieve a comparable displacement performance.

[0006] In principle, a microelectromechanical component can be, for example, a semiconductor-based device with mechanical and electrical microstructures. Due to its microstructural design, a microelectromechanical component can be suitable for implementation as a system-on-a-chip (SoC). Microelectromechanical components can be used, for example, as miniaturized sensors or actuators.

[0007] The substrate of the microelectromechanical device can be a planar semiconductor support structure. The substrate can, for example, be a silicon wafer. The substrate can have two opposing substrate surfaces, each with a larger area than a single lateral surface connecting the substrate surfaces. The substrate recess can form a through-hole through the substrate, laterally bounded by the substrate frame. The substrate frame can form a substantially closed frame structure that completely surrounds and encloses the substrate recess. The substrate frame can, for example, have a rectangular base. Furthermore, as will be explained below, the substrate recess can be at least partially bounded by a cover substrate and / or a base substrate.The substrate frame with at least one displacement element can be arranged, in particular, between the cover substrate and the base substrate. Optionally, at least one support wall can extend parallel to the substrate frame through the substrate recess to provide the microelectromechanical component with improved mechanical stability.

[0008] At least one displacement element extends within the substrate recess. In particular, several displacement elements can extend within the substrate recess. These multiple displacement elements can be arranged essentially parallel to one another when in a resting state. The features described below with respect to a single displacement element can be applied analogously to further displacement elements within the same substrate recess. The displacement element serves as a movable structure for the controlled displacement of a fluid volume, for example, for fluid conveyance or for generating an acoustic signal. The displacement element can separate two adjacent volumes, forming fluid chambers for conveying and displacing fluid. The fluid chambers are variable in size, and in particular, their size can be reduced or increased, by means of the deflectable displacement element.This allows a fluid, for example a gas mixture such as air, to be drawn in and displaced.

[0009] The displacement element can, for example, be used as an actuator. For this purpose, the displacement element can be driven by a drive unit, for example, based on an electrostatic or piezoelectric drive principle. It is also conceivable that the displacement element could function as a sensor element. This could, for example, be configured to detect a sound signal based on a measurable displacement of the displacement element. For use as a sensor element, the microelectromechanical component could include, for example, an electrostatic sensing device to detect a displacement of the displacement element.

[0010] The displacement element can, for example, be designed as an elongated bending beam. The displacement element can form a planar lamella that may be suspended vertically within the microelectromechanical device. A vertical orientation of the lamella can mean that a principal plane of extension of the lamella runs essentially perpendicular to a substrate surface. The displacement element can, in particular, be integral, i.e., formed as a single piece with the substrate. For example, the displacement element may have been separated from the substrate during a manufacturing process of the microelectromechanical device, such as during an etching step to create the substrate recess.

[0011] The displacement element can have a longitudinal extension from a first frame section to a second frame section of the substrate frame, particularly one located opposite the first. This longitudinal extension can correspond to a principal extension of the displacement element. The displacement element can have a lateral extension from a third frame section, perpendicular to the first frame section, to a fourth frame section, particularly one located opposite the first. The longitudinal and lateral extensions can define a horizontal extent of the displacement element. The displacement element can have a vertical extension parallel to the first frame section, perpendicular to both the longitudinal and lateral extensions. The vertical extension can define a vertical extent of the displacement element.

[0012] The displacement element can be elastically deflectable. Upon removal of the driving or pressure force that deflects the displacement element, it can automatically return to its original position. The length of the displacement element can essentially correspond to the length of the substrate recess to achieve optimized utilization of the available installation space and high displacement rates with low fluidic leakage. The height of the displacement element can also essentially correspond to the height of the substrate recess. If the substrate recess is largely enclosed by the substrate frame, a cover substrate, and a base substrate, a particularly low fluidic leakage rate can be achieved by using the same length and height for the displacement element and the substrate recess, thus enabling high displacement performance.

[0013] The stiffness reduction section can be a local area of ​​the displacer element where it exhibits reduced stiffness compared to other areas. The stiffness of the displacer element can refer specifically to the component and / or material stiffness of the displacer element itself. For example, the Young's modulus of the section under consideration can be used as a characteristic value for the stiffness of the displacer element. The reduced stiffness can be achieved, for example, through geometric adaptation, a specific crystal orientation, or other properties of the section that selectively influence its stiffness. The displacer element can also have several stiffness reduction sections, which, depending on the embodiment, may be directly adjacent to one another or spaced apart.

[0014] According to one embodiment, at least one displacer element of the microelectromechanical component can have a second mounting section with which the displacer element is attached to a second frame part of the substrate frame. This achieves a defined separation of volumes, which are separated from one another by the displacer element, thus preventing fluid leakage between the volumes. The second frame part can, for example, be arranged opposite the first frame part. This allows for stable, two-sided clamping of the displacer element on opposite sides of the substrate frame.

[0015] According to one embodiment, at least one displacer element of the microelectromechanical component can have a free end facing a second frame part of the substrate frame. This allows for one-sided clamping of the displacer element, resulting in lower longitudinal stiffness and consequently greater deflection of the displacer element. The second frame part can, for example, be arranged opposite the first frame part. In a rest state, the displacer element can thus extend essentially straight through the substrate recess and point towards the second frame part. The free end of the displacer element can, for example, rest loosely against the second frame part or be spaced apart from it, creating a gap.It is also conceivable that several displacement elements extend within the substrate recess, at least one of which is attached to the first frame part by a first mounting section and has a free end facing the second frame part, and at least one further displacement element is attached to the second frame part by a first mounting section and has a free end facing the first frame part. Such an attachment of the displacement elements to the first and second frame parts, particularly an alternating attachment, can improve the fluid conveying and displacement behavior as well as the stability of the microelectromechanical component.

[0016] In principle, embodiments of the microelectromechanical component are also conceivable in which at least one displacement element of the microelectromechanical component has a second mounting section with which the displacement element is attached to the second frame part of the substrate frame, and at least one further displacement element of the microelectromechanical component has a free end that faces a second frame part of the substrate frame. This allows the advantages of both embodiments to be combined in a single microelectromechanical component.

[0017] According to one embodiment, the stiffness-reducing section can be connected to the first mounting section and / or to the second mounting section. Alternatively or additionally, the stiffness-reducing section can be arranged between the first and second mounting sections. This allows for the creation of a segmented displacer element that exhibits different properties, particularly different stiffnesses, in each segment. The stiffness of the displacer element in the first and / or second mounting section can differ significantly from the stiffness of the displacer element in the stiffness-reducing section. In particular, the stiffness of the displacer element in the first and / or second mounting section can be significantly higher than in the stiffness-reducing section.This allows for a greater displacement of the displacement element in an area spaced away from the substrate frame. At the same time, stable clamping of the displacement element can be achieved for controlled displacement.

[0018] If the displacement element, in a two-sided clamping arrangement, has a first and second mounting section connected to a first and a second frame section of the substrate frame, the first and second mounting sections can be connected to each other via the stiffness-reducing section. Alternatively, it is conceivable that the stiffness-reducing section connects to the first and / or the second mounting section, but that at least one further element section exists between the first and second mounting sections, exhibiting a stiffness different from that of the stiffness-reducing section.Furthermore, it is also conceivable that the stiffness-reducing section is located between the first and second mounting sections, but is separated from them by at least one further element section with a different stiffness. If the displacement element has a first mounting section and a free end in the case of a one-sided clamping, the stiffness-reducing section can optionally be directly connected to the first mounting section or separated from it by another element section with a different stiffness. According to one embodiment, the stiffness-reducing section can extend completely from the first mounting section to the free end, thus ensuring a high degree of deflection.

[0019] According to one embodiment, the first mounting section and / or the second mounting section can be angled to a principal extension direction of the displacer element, and / or the stiffness-reducing section can be angled to a principal extension direction of the displacer element. The principal extension direction of the displacer element can correspond to a spatial direction along which the displacer element has its principal extension. In particular, the principal extension direction can correspond to a horizontal spatial direction of the longitudinal extension of the displacer element. The principal extension direction of the displacer element can, for example, be defined by a maximum extension of the displacer element with respect to its three-dimensional extent.The principal extension direction can be defined, for example, by an extension of the displacer element between the first frame part and a frame part of the substrate frame opposite the first frame part. The principal extension direction of the displacer element can also be defined, for example, as an extension of the displacer element parallel to a frame part of the substrate frame that is substantially perpendicular to the first frame part of the substrate frame. The first mounting section and / or the second mounting section can, in particular, be angled to a principal extension plane of the displacer element. The principal extension plane of the displacer element can be perpendicular to a substrate surface. The principal extension plane can, in particular, be defined by a longitudinal extension and a vertical extension of the displacer element.

[0020] By angling the displacement element section by section, different stiffness properties can be easily achieved in an angled section compared to a non-angled section. This effect can be due, for example, to the anisotropic properties of many substrate materials. Different stiffness properties in an angled section compared to a non-angled section allow, for instance, a stable clamping of the displacement element combined with high deflection capability. Depending on the properties of the substrate material, the desired differential stiffness can be achieved by angling the stiffness-reducing section or by angling a mounting section.The angling can be achieved, for example, by an angle between 30° and 60° (according to a 360° angle system) formed between the mounting section under consideration and the main extension direction of the displacement element. In particular, the angling can be achieved by an angle of 45° ± 10° formed between the mounting section under consideration and the main extension direction of the displacement element. If the first mounting section and the second mounting section are each angled to the main extension direction of the displacement element, they can be arranged, for example, axially symmetrically or rotationally symmetrically to each other, depending on the chosen embodiment.

[0021] An angled first and / or second mounting section relative to the main extension direction of the displacement element can be accompanied by an angled first mounting section relative to the first frame member and / or an angled second mounting section relative to the second frame member, each angle being non-90°. The first mounting section can therefore be angled obliquely from the first frame member and / or the second mounting section can be angled obliquely from the second frame member. Furthermore, it is conceivable that the first and / or second mounting section runs at an angle to the stiffness-reducing section.

[0022] According to one embodiment, the first and / or second mounting section can be designed as a stiffness-reducing section. Accordingly, the first and / or second mounting section itself can exhibit reduced stiffness compared to other element sections of the displacement element, thus achieving a flexible, and in particular elastic, clamping of the displacement element. Such an embodiment results in a significantly reduced longitudinal stiffness of the displacement element. Furthermore, compared to displacement elements with comparatively rigid clamping, a larger deflectable area of ​​the displacement element is achieved, since flexibly clamped displacement elements can deflect over a large portion of their mounting area.

[0023] According to one embodiment, the displacement element can have a stiffening section with a higher stiffness than the stiffness-reducing section. Thus, the stiffness of the entire displacement element is not necessarily reduced, but rather it has sections of higher and lower stiffness to selectively optimize the deflection behavior and stability of the displacement element locally. In other words, a segmented displacement element is provided, comprising at least two segments with different stiffness properties. The stiffening section and the stiffness-reducing section can, for example, be arranged directly or spaced apart along the main extension direction of the displacement element.

[0024] According to one embodiment, the first mounting section and / or the second mounting section can be designed as a stiffening section. Accordingly, the first and / or second mounting section of the displacement element has increased stiffness compared to the stiffness-reducing section. This allows for stable mounting of the displacement element while maintaining a defined high deflection of the displacement element within the stiffness-reducing section.

[0025] According to one embodiment, the stiffening section can be connected to the first mounting section or to the second mounting section. Alternatively or additionally, the stiffening section can be arranged between the first and second mounting sections. This allows for the creation of a segmented displacement element with differing stiffness properties in the first and / or second mounting section compared to the stiffening section. For example, at least one mounting section of the displacement element can be designed as a stiffness-reducing section.A stiffening section, connected to or between the first and second mounting sections, allows for relatively flexible clamping while increasing the stability of the displacer element within a deflection range, such as the middle or remaining portion of the displacer element extending from the mounting section. This enables a defined and well-controlled deflection of the displacer element, as it avoids, for example, additional vibration modes or a reduced natural frequency resulting from excessive flexibility of the displacer element within the deflection range.

[0026] If the displacement element, in a two-sided clamping arrangement, has a first and second mounting section connected to a first and second frame section of the substrate frame, the first and second mounting sections can be connected to each other via the stiffening section. Alternatively, the stiffening section can be connected to the first and / or second mounting section, but at least one further element section exists between the first and second mounting sections, exhibiting a stiffness different from that of the stiffening section. Furthermore, the stiffening section can also be located between the first and second mounting sections, but separated from them by at least one further element section, each with a different stiffness.If the displacement element, when clamped on one side, has a first mounting section and a free end, the stiffening section can optionally connect directly to the first mounting section or be spaced apart from it by a further element section with a different stiffness. According to an advantageous embodiment, the stiffening section can extend completely from the first mounting section to the free end, thus ensuring high stability of the displacement element in the deflection range.

[0027] According to one embodiment, the stiffening section can include a flywheel element. This allows for targeted deflection amplification when the displacer element is deflected. The flywheel element can, in particular, be integral with the displacer element. The flywheel element can, in particular, extend over the entire height of the displacer element. The flywheel element can form an inertial body to amplify the deflection. The flywheel element can, for example, be considered a horizontal thickening structure of the displacer element. The term "vertical" can refer to a direction of extension of the displacer element perpendicular to a principal direction of extension of the displacer element between the frame members of the substrate frame. The flywheel element can, for example, represent a local thickening of the displacer element along a height extension of the displacer element.The inertia element can be formed by a local change in the cross-section of the displacement element. The inertia element can form a lateral projection on the displacement element. The stiffening section can also have several, i.e., at least two, spaced-apart inertia elements. In the case of a displacement element with a free end, the inertia element can be arranged in a region adjacent to the free end, so that the displacement element experiences additional deflection amplification in the region of its maximum deflection. In the case of a displacement element with two-sided clamping with a first and second mounting section, the inertia element can be arranged substantially midway between the first and second mounting sections, so that the displacement element experiences additional deflection amplification in the region of its maximum deflection.The flywheel element can, for example, be block-shaped. A block-shaped flywheel element can, in particular, be arranged at a free end of a displacer element clamped on one side. The flywheel element can, for example, be designed as a cross brace. Advantageously, several cross braces can be combined on one displacer element. A flywheel element designed as a cross brace can, in particular, be arranged substantially centrally between the first and second mounting sections of a displacer element clamped on both sides.

[0028] According to one embodiment, the substrate and the displacer element can be monocrystalline, and the stiffness-reducing section can have a first crystal orientation along a principal extension plane of the displacer element in a range of ±30° around the (100) crystal plane. In the surface region of the described crystal orientation of a monocrystalline substrate, there is a reduced Young's modulus compared to surface planes with other crystal orientations. If the stiffness-reducing section along the principal extension plane of the displacer element has a crystal orientation between -30° and +30° around a (100) crystal plane, a larger displacement of the displacer element can be efficiently achieved, resulting in increased displacer performance. The principal extension plane of the displacer element can be perpendicular to a substrate surface.The main extension plane can be defined in particular by a longitudinal extension and a vertical extension of the displacement element.

[0029] According to one embodiment, the stiffness-reducing section along the principal extension plane of the displacer element can have a first crystal orientation along the (100)-crystal plane. For surface planes with such a crystal orientation, there is a significantly reduced Young's modulus, which is reduced by up to 30% compared to the Young's moduli of surface planes with other crystal orientations.

[0030] To simplify the description of the crystal orientations, the following atomic numbers will be used: The first crystal orientation corresponds to a crystal orientation along the (100) crystal plane. The second crystal orientation corresponds to a crystal orientation along the (100) crystal plane. The third crystal orientation corresponds to a crystal orientation along the (010) crystal plane. The fourth crystal orientation corresponds to a crystal orientation along the (010) crystal plane. The fifth crystal orientation corresponds to a crystal orientation along the (001) crystal plane. The sixth crystal orientation corresponds to a crystal orientation along the (001) crystal plane. The seventh crystal orientation corresponds to a crystal orientation along the (110) crystal plane. The eighth crystal orientation corresponds to a crystal orientation along the (110) crystal plane.

[0031] According to one embodiment, the substrate can have a substrate surface with a fifth crystal orientation along the (001) crystal plane. This allows a suitable crystal orientation for the design of the stiffness-reducing section to be achieved simply and effectively, according to the crystal orientations described above along the principal extension plane of the displacer element. Thus, a substrate with a specific crystal orientation can be used for the fabrication of the microelectromechanical device. While conventional standard substrates are designed such that orthogonal structural edges are aligned along the (110) and (110) crystal planes, the substrate used for the described embodiment can, for example, be designed such that orthogonal structural edges are aligned along the (010) and (100) crystal planes.

[0032] According to one embodiment, the stiffening section can have a crystal orientation that differs from the first crystal orientation along a principal extension plane of the stiffening section. Thus, the crystal orientation of the stiffening section can deviate from a (100) crystal plane. This allows for the simple provision of a stiffening section with a comparatively high stiffness. A higher Young's modulus is present with a deviating crystal orientation than with a crystal orientation along the (100) crystal plane. If the displacer element has a stiffness-reducing section along the principal extension plane of the displacer element with a crystal orientation along the (100) crystal plane, as well as a stiffening section with a crystal orientation that differs from the (100) crystal plane, sections with high and low stiffness can be easily combined.The stiffening section can, for example, be angled from the main extension plane of the displacer element in order to easily obtain a different crystal orientation.

[0033] According to one embodiment, the displacer element can transition into the substrate frame with a third crystal orientation along the (010) crystal plane and / or with a fourth crystal orientation along the (010) crystal plane. These crystal orientations can correspond to an alignment of a transition surface between the displacer element and the substrate frame and ensure a firm anchoring of the displacer element to the substrate frame. Depending on whether the displacer element is clamped on one or both sides, only one or two transition surfaces of the displacer element can be aligned with the substrate frame along the described crystal orientations.

[0034] According to one embodiment, the displacer element in the first mounting section and / or in the second mounting section can have a crystal orientation that differs from the first crystal orientation along the principal extension plane of the displacer element. Thus, the crystal orientation of the first and / or second mounting section can deviate from a (100) crystal plane. This allows for the simple provision of one or two mounting sections with comparatively high stiffness. In other words, the first and / or the second mounting section can form a stiffening section. With a deviating crystal orientation, a higher Young's modulus is present than with a crystal orientation along the (100) crystal plane.If the displacer element has a stiffness-reducing section along its principal extension plane with a crystal orientation along the (100) crystal plane, and a fixing section with a crystal orientation differing from the (100) crystal plane, sections with high and low stiffness can be easily combined. The first and / or second fixing section can, for example, be angled from the principal extension plane of the displacer element to easily achieve a different crystal orientation.

[0035] According to one embodiment, the stiffness-reducing section can be configured as a bifurcation section. A bifurcation section can feature a local bifurcation or multiple branching of the displacer element. Such a local geometric adaptation of the displacer element allows for a simple and efficient reduction of stiffness within the stiffness-reducing section. This significantly reduces the longitudinal stiffness of the displacer element, enabling larger deflections of the displacer element, at least within the stiffness-reducing section. Within the bifurcation section, the displacer element can divide into two or more legs along its longitudinal extent. The two or more legs can merge into a common leg at one end of the bifurcation section.The two or more legs can each be at least as long as the common leg. Designing a stiffness-reducing section in the form of a bifurcation can be particularly advantageous in combination with a two-sided clamping, as this allows for a significant reduction in the longitudinal stiffness of the displacement element. In a deflected state of the displacement element, the bifurcation section can be stretched on one side of the element and compressed on the other side. This behavior of the bifurcation section can, for example, support elastic recovery of the displacement element.

[0036] According to one embodiment, the displacer element can have multiple bifurcation sections. This allows for the defined formation of stiffness-reduced areas to optimize the displacement behavior and stability of the displacer element. A high degree of freedom exists in the geometric design of the displacer element with respect to the bifurcation sections. For example, similar or different bifurcation geometries and dimensions can be combined. Furthermore, simple and complex bifurcation geometries can be realized, for example, through lithographic masking processes during the fabrication of the microelectromechanical component. The multiple bifurcation sections can be arranged directly consecutively along a main extension direction of the displacer element and / or spaced apart from one another.

[0037] According to one embodiment, the first mounting section and / or the second mounting section can be designed as a bifurcation section. This allows for a reduced stiffness clamping, resulting in a flexible, and in particular elastic, attachment of the displacer element to the substrate frame. In this way, a significantly reduced longitudinal stiffness of the displacer element can be achieved. Furthermore, compared to rigidly clamped displacer elements, a larger deflectable area of ​​the displacer element is obtained, since flexibly clamped displacer elements can be deflected over a large portion of their mounting area. Additionally, mechanical stress peaks at the transition to the substrate frame can be avoided by the flexible clamping, thereby increasing the robustness of the displacer element. Finally, vertical snapping of the displacer element against the cover and base substrate can be prevented.The first fastening section and / or the second fastening section can, for example, be designed as fork-shaped bifurcation sections.

[0038] According to one embodiment, at least one bifurcation section of the displacement element can be arranged between the first mounting section and the second mounting section. This allows for a greater deflection of the displacement element in a region spaced apart from the substrate frame. The clamping of the displacement element can be designed independently of the intended bifurcation section and, for example, made relatively rigid by means of a stiffening section. The bifurcation section can, for example, be arranged essentially centrally between the first mounting section and the second mounting section.

[0039] According to one embodiment, at least one bifurcation section of the displacement element can have a polygonal outer contour. The polygonal outer contour can, for example, be quadrilateral, rectangular, square, or diamond-shaped, thus providing a simple symmetrical geometry for the bifurcation section. Alternatively, the polygonal outer contour can be hexagonal, for example, or constricted, or octagonal. Hexagonal or octagonal outer contours allow for bifurcation sections with comparatively long legs, which can significantly reduce stiffness in the bifurcation section.

[0040] According to one embodiment, at least one bifurcation section of the displacement element can have a rounded outer contour. This allows for favorable force flow guidance and avoids mechanical stress concentrations in the bifurcation section. A bifurcation section with a rounded outer contour can, in particular, have a circular or elliptical outer contour.

[0041] According to one embodiment, several successive bifurcation sections can jointly form a meandering outer contour. A meandering outer contour can be formed, for example, by regular, repeating angled or curved contours along an imaginary straight corridor along the bifurcation sections. The meandering outer contour can, for example, have a square, triangular, or wave-like basic shape. A meandering outer contour can achieve increased flexibility of the displacement element and can be used, for example, to optimize the extension and bending of the deflected displacement element.

[0042] According to one embodiment, the bifurcation section can extend over the entire displacement element. Alternatively, several successive bifurcation sections can extend over the entire displacement element. This allows for particularly high flexibility of the displacement element. Accordingly, the displacement element can predominantly run in a forked or branched form between the first frame part and the second frame part of the substrate frame. In the case of successive bifurcation sections, the displacement element can be single-legged at the transition between the bifurcation sections and two-legged or multi-legged within the bifurcation sections themselves. The transition between two bifurcation sections can form a hinge structure between the bifurcation sections, thereby increasing the mobility of the displacement element.Alternatively, the entire displacement element can be designed as a bifurcation section, i.e., it can be forked or branched completely along its longitudinal extent.

[0043] According to one embodiment, the first mounting section and / or the second mounting section can have a stepped profile, a profile angled obliquely to the substrate frame, or a curved profile, with which the displacer element transitions into the substrate frame. This ensures a stepwise or continuous transition of the displacer element into the substrate frame, which can prevent mechanical stress concentrations in the displacer element and effectively increase the robustness of the displacer element, for example, in overload situations.

[0044] According to one embodiment, the first fastening section and / or the second fastening section can have a curved profile with a radius of curvature of at least 5 µm. This allows for a particularly smooth and gradual transition of the displacer element into the substrate frame, resulting in a particularly robust and low-stress anchoring of the displacer element to the substrate frame.

[0045] According to one embodiment, the first fastening section and / or the second fastening section can have a profile angled obliquely to the substrate frame with a transition surface exhibiting a seventh crystal orientation along the (110) crystal plane. This allows for a low-stress profile of the first and / or second fastening section with increased stiffness and stability in the fastening area. In particular, the transition surface along the (110) crystal plane in the considered fastening section can have a higher Young's modulus than a principal extension plane of the displacer element in a stiffness-reducing section of the displacer element, which can, in particular, have a crystal orientation in a range of ±30° around a (100) crystal plane or a crystal orientation along the (100) crystal plane along the principal extension plane of the displacer element.The transition surface of the first and / or second fastening section can, for example, be defined by a length and height extension of the displacement element in the fastening section under consideration.

[0046] According to one embodiment, an electrode device arranged transversely to the displacement element at its vertical end can be provided for deflecting the displacement element. This enables targeted deflection of the displacement element that can be controlled over a wide range. The electrode device arranged transversely to the displacement element can, in particular, extend substantially parallel to a longitudinal and a lateral extent of the displacement element. In other words, the displacement element and the electrode device can be arranged in a T-shape relative to each other in a cross-sectional view, sharing a common longitudinal direction. The vertical end can be defined as an end region or a termination surface of the displacement element with respect to its vertical extent. The microelectromechanical component can, in particular, have several electrode devices for deflecting the displacement element.These can, for example, be arranged at the opposite ends of the displacement element.

[0047] According to one embodiment, the electrode device can span the first mounting section or the second mounting section. In other words, the electrode device can have a greater width than the mounting section projecting towards or facing the electrode device. This allows the electrode device to generate an extensive electric field, providing a large deflection range for the displacement element.

[0048] The invention also relates to a microelectromechanical component comprising a microelectromechanical element according to one of the features described above, a base substrate at least partially covering the substrate recess, a cover substrate at least partially covering the substrate recess, at least one fluid opening in the base substrate and / or in the cover substrate, and a drive device for generating a deflection of the displacement element and / or a detection device for detecting a deflection of the displacement element. This allows for the provision of a component that is largely enclosed, except for the fluid openings, for utilizing the displacement principle achievable with the displacement element. The proposed microelectromechanical component can also achieve the advantages of high displacement performance described above.The base substrate and the cover substrate can be designed to define the volumes separated from each other by the displacement element. The cover substrate and / or the base substrate can each be formed, for example, by a silicon wafer. The substrate frame with the at least one displacement element can be arranged, in particular, between the cover substrate and the base substrate. The substrate recess can be largely closed by the base substrate and the cover substrate, with the exception of the fluid openings. At least partial coverage can indicate that a fluid connection to the environment of the microelectromechanical component may exist, at least in the area of ​​the fluid openings. The fluid openings can, for example, be arranged alternately in the base substrate and in the cover substrate with respect to the adjacent volumes separated from each other by the displacement element.The volumes can form fluid chambers, whereby adjacent fluid chambers can be complementarily reduced in size and enlarged when the displacement element is deflected. The drive unit for generating a deflection of the displacement element can, for example, be an electrostatic or piezoelectric drive unit. The detection unit for detecting a deflection of the displacement element can, for example, be an electrostatic or piezoelectric detection unit. Depending on the drive unit and / or detection unit provided on the microelectromechanical component, it can be used as an actuator and / or sensor component.

[0049] According to one embodiment, the microelectromechanical component can be configured as a sound transducer. This allows the microelectromechanical component to be used, for example, in a loudspeaker or a microphone. A sound transducer can be configured to generate and / or detect sound waves. In other words, a sound transducer can be configured to displace air at an audible frequency and / or to detect pressure-induced vibrations in an audible frequency range. For example, the sound transducer can be configured to convert an electrical signal applied to the sound transducer into a mechanical displacement of the displacement element and / or to convert a mechanical displacement of the displacement element into an electrical signal. The improved displacement of the displacement element allows high sound levels to be generated and / or detected with high signal quality.In principle, the microelectromechanical component can also be used for other applications. For example, the microelectromechanical component can alternatively be configured as a microfluidic component and used, for instance, in a micropump.

[0050] The invention also relates to a microelectromechanical device comprising a microelectromechanical component according to one of the features described above and a signal processing unit for applying, receiving, and / or processing signals from the microelectromechanical component. This provides a ready-to-use microelectromechanical device comprising a microelectromechanical actuator and / or sensor structure according to the preceding descriptions and an associated control unit. Due to the improved microelectromechanical component, the proposed microelectromechanical device also achieves the advantages of high displacement power described above. The signal processing unit can include an evaluation and / or control circuit, which can be designed, in particular, as an integrated circuit, for example, as an ASIC (application-specific integrated circuit).

[0051] According to one embodiment, the microelectromechanical device can be configured as a microelectromechanical loudspeaker. This allows the higher displacement power achievable with the improved microelectromechanical component to be converted into sound signals with high sound levels and high signal quality, despite the small size of the microelectromechanical device. The microelectromechanical loudspeaker can, for example, include a previously described transducer component and a control unit for generating sound waves by means of the displacement element in response to an electrical audio signal. In principle, the microelectromechanical device can also be used for other applications. For example, the microelectromechanical device can be configured as a microelectromechanical microphone or a microelectromechanical micropump.

[0052] In general, in connection with this application, the words "ein / eine" are not to be understood as numerals, unless expressly defined otherwise, but as indefinite articles with the meaning of "at least one".

[0053] The invention allows for various embodiments and is explained in more detail below with reference to exemplary embodiments and the accompanying drawings. These show, in schematic form: Fig. 1 - a schematic diagram of a microelectromechanical component according to one embodiment in a cutaway front view; Fig. 2 - a top view of a microelectromechanical component according to a first embodiment with displacement elements in a rest state; Fig. 3 - a top view of the in Fig. 2 microelectromechanical component shown according to the first embodiment with displacement elements in a deflected state; Fig. 4 - an isolated perspective partial view of a displacement element of the microelectromechanical component according to the first embodiment; Fig. 5 - a top view of a microelectromechanical component according to a second embodiment with displacement elements in a deflected state; Fig. 6 - a top view of a microelectromechanical component according to a third embodiment with displacement elements in a deflected state; Fig. 7 - a top view of a microelectromechanical component according to a fourth embodiment with displacement elements in a rest state; Fig. 8 - a top view of a microelectromechanical component according to a fifth embodiment with displacement elements in a rest state; Fig. 9 - an isolated perspective partial view of a displacement element of a microelectromechanical component according to a first embodiment variant; Fig. 10 - an isolated perspective partial view of a displacement element of a microelectromechanical component according to a second embodiment; Fig. 11 - an isolated perspective partial view of a displacement element of a microelectromechanical component according to a third embodiment; Fig. 12 - a top view of a two-sided mounted displacement element of a microelectromechanical component in a rest state according to a sixth embodiment; Fig. 13 - a top view of a two-sided mounted displacement element of a microelectromechanical device in a rest state according to a seventh embodiment; Fig. 14 - a top view of a double-sided mounted displacement element of a microelectromechanical component in a rest state according to an eighth embodiment; Fig. 15 - a top view of a double-sided mounted displacement element of a microelectromechanical component in a rest state according to a ninth embodiment; Fig. 16 - a top view of a two-sided mounted displacement element of a microelectromechanical component in a rest state according to a tenth embodiment; Fig. 17a - a top view of a two-sided mounted displacement element of a microelectromechanical device in a rest state according to the sixth embodiment; Fig. 17b - a top view of the two-sided mounted displacement element of the microelectromechanical component in a deflected state according to the sixth embodiment; Fig. 18 - a top view of a two-sided mounted displacement element of a microelectromechanical component in a rest state according to an eleventh embodiment; Fig. 19 - a top view of a double-sided mounted displacement element of a microelectromechanical component in a rest state according to a twelfth embodiment; Fig. 20 - a top view of a double-sided mounted displacement element of a microelectromechanical component in a rest state according to a thirteenth embodiment; Fig. 21 - an isolated perspective view of a displacement element of a microelectromechanical component with electrode devices extending transversely to the displacement element; Fig. 22 - a schematic diagram of a microelectromechanical device with a microelectromechanical component.

[0054] Fig. Figure 1 shows a front view of a microelectromechanical component 18 according to one embodiment. The microelectromechanical component 18 comprises a microelectromechanical element 1. The microelectromechanical element 1 has a substrate 2 with a substrate recess 3 bounded by a substrate frame 2a. The substrate recess 3 is predominantly covered by a cover substrate 15 and a base substrate 16. Several displacement elements 4 extend within the substrate recess 3. These elements are at least partially deflectable, in particular elastically deflectable, and can be considered as elongated bending beams or as lamellae suspended vertically in the microelectromechanical element 1. In a rest state, the displacement elements 4 extend substantially parallel to one another.The displacement elements 4 are, in particular, integrally formed with the substrate 2, for example, when the substrate recess 3 is produced from the substrate 2. The microelectromechanical component 18 has a drive unit 14 with electrode devices 13, with which the displacement elements 4 can be deflected based on an electrostatic drive principle. For example, two displacement elements 4 can be moved towards each other, as illustrated by the arrows, to displace a fluid volume located between them through a fluid opening 17 in the cover substrate 15 and to draw in another fluid volume through a fluid opening 17 in the base substrate 16 in an adjacent fluid chamber. Due to the displacement principle described, the microelectromechanical component 18 can be used, for example, for fluid conveying or for generating acoustic signals.The substrate frame 2a can be arranged between the cover substrate 15 and the base substrate 16. Additionally, as shown, at least one support wall 22 can be arranged between the cover substrate 15 and the base substrate 16 to increase the mechanical stability of the microelectromechanical component 18.

[0055] The Fig. 2 and Fig. Figure 3 shows a schematic top view of a microelectromechanical component 1 according to a first embodiment. Fig. 2 the microelectromechanical component 1 with displacer elements 4 in a rest state, while Fig. Figure 3 illustrates the microelectromechanical component 1 with deflected displacement elements 4. The displacement elements 4 of the microelectromechanical component 1 according to the first embodiment are anchored by a first mounting section 5 to a first frame part 2a-I of the substrate frame 2a and by a second mounting section 6 to a second frame part 2a-II, which is opposite the first frame part 2a-I. In other words, the displacement elements 4 are clamped on two sides, thereby enabling a defined separation of the respective volumes separated from each other by the displacement elements 4 and preventing fluid leakage between the volumes.Between the first mounting sections 5 and the second mounting sections 6, the displacement element 4 extends, each with a stiffness-reducing section 7 in which the stiffness is lower than in the first and second mounting sections 5, 6 of the displacement elements 4. Due to the reduced stiffness of the displacement elements 4 in the stiffness-reducing sections 7, large deflections of the displacement elements 4 can be achieved, thus enabling high displacement performance.

[0056] To achieve the reduced stiffness in the stiffness reduction section 7, the substrate 2 and the displacement element 4 are monocrystalline, and the stiffness reduction section 7 has, for example, a profile extending along a Fig. Figure 4 illustrates the principal extension plane H of the displacer element 4, which exhibits a first crystal orientation K1 along the (100) crystal plane. Due to the anisotropic properties of the substrate 2, it can be exploited that a reduced Young's modulus exists along the (100) crystal plane of the substrate 2 compared to surface planes with other crystal orientations. Thus, the stiffness of the displacer elements 4 can be efficiently reduced by cleverly utilizing the different direction-dependent properties of the substrate 2, and a higher displacement performance can be achieved through flexible displacer elements 4. A comparable effect can also be achieved within a range of ±30° around the (100) crystal plane, whereby the Young's modulus along the (100) crystal plane can be minimized. The principal extension plane H of a displacer element 4 can, for example, be defined by a Fig. Figure 4 illustrates the vertical extent c and the longitudinal extent b of the displacement element 4. A lateral extent a of the displacement element can be perpendicular to the vertical extent c and the longitudinal extent b. A principal extent h of the displacement elements 4 can be defined as shown in Fig. 2 can be defined by the longitudinal extent b of the displacement elements 4. The principal extent plane H of the displacement element 4 can, for example, run essentially perpendicular to a substrate surface 2b of the substrate 2.

[0057] To realize a first crystal orientation K1 along the (100)-crystal plane in the principal extension plane H of the displacer element 4, the substrate 2 can have a substrate surface 2b with a fifth crystal orientation K3 along the (001)-crystal plane, as is the case, for example, with the Fig. 4 is removable. As in Fig. As indicated in Figure 2, orthogonal structures of the microelectromechanical device 1 can be aligned along the first crystal orientation K1 along the (100) crystal plane and along a third crystal orientation K2 along the (010) crystal plane.

[0058] As shown by the Fig. As can be seen in section 2, the stiffness reduction section 7 of the displacement elements 4 connects to the first mounting section 5 and the second mounting section 6. The stiffness reduction section 7 is positioned between the first mounting section 5 and the second mounting section 6. This allows the deflection capability of the displacement elements 4 to be specifically increased in the ranges of higher movement amplitudes. Segmented displacement elements 4 are thus provided, which can combine stable clamping with large deflections.

[0059] In Fig. Figure 3 shows the displacement elements 4 of the microelectromechanical component 1 according to the first embodiment in a deflected state. It can be seen that a pronounced deflection of the displacement elements 4 is achievable due to the stiffness-reducing sections 7.

[0060] In Fig. Figure 4 shows a perspective partial view of a displacement element 4 of the microelectromechanical component 1 according to the first embodiment, which is connected to the first frame part 2a-I of the substrate frame 2a by a first mounting section 5. According to the illustrated embodiment, the displacement element 4 transitions into the substrate frame 2a in a straight mounting section 5. Fig. Figure 4 illustrates advantageous crystal orientations of the surface planes of the displacing element 4. Accordingly, a principal extension plane H of the displacing element 4, spanned by a height extension c and a longitudinal extension b of the displacing element 4, can have a first crystal orientation K1 along the (100) crystal plane. A corresponding opposite second crystal orientation K1' can correspond to a crystal orientation in the (100) crystal plane. The displacing element 4 can transition into the substrate frame 2a, for example into the second frame part 2a-II, with a third crystal orientation K2, and into the substrate frame 2a, for example into the first frame part 2a-I, with a fourth crystal orientation K2'. The substrate surface 2b can have a fifth crystal orientation K3 along the (001) crystal plane.A corresponding opposite sixth crystal orientation K3' can correspond to a crystal orientation in the (001) crystal plane.

[0061] By selecting the crystal orientation in the principal extension plane H of the displacer element 4 along the (100)-crystal plane, a minimization of the modulus of elasticity can be exploited in order to selectively influence the stiffness properties of the displacer element 4 in the region of its deflection and to achieve larger deflections.

[0062] Fig. Figure 5 shows a top view of a microelectromechanical component 1 according to a second embodiment with displacement elements 4 in a deflected state. Some of the displacement elements 4 shown are attached to a first frame part 2a-I by a first mounting section 5 and have a free end 8 that faces the second frame part 2a-II of the substrate frame 2a, but is not connected to the second frame part 2a-II. Other displacement elements 4 shown are attached to the second frame part 2a-II by a first mounting section 5 and have a free end 8 that faces the first frame part 2a-I of the substrate frame 2a, but is not connected to the first frame part 2a-I. In other words, the displacement elements 4 are clamped at one end. The free ends 8 can be spaced away from the respective nearest first or second frame part 2a-I, 2a-II as shown, forming a free space.Due to their free ends 8, the displacement elements 4 exhibit negligible longitudinal stiffness and therefore generally good deflection capability. The alternating mounting of the displacement elements 4 improves the fluid conveying and displacement behavior as well as the stability of the microelectromechanical component 1. As shown by the... Fig. As can be seen in section 5, a stiffness-reducing section 7 is attached to the first mounting section 5 of the displacer elements 4, so that the deflection of the displacer elements 4 away from the substrate frame 2a can be further increased. As in the first embodiment described above, the stiffness-reducing sections 7 can have a lower stiffness than, for example, the first mounting section 5 or the stiffening section 9 described below, by aligning the main extension plane H of the displacer elements 4 according to the first crystal orientation K1 along the (100) crystal plane. Fig. It is therefore further evident from Figure 5 that stiffening sections 9 are formed at the free ends 8 of the displacement elements 4, in which the displacement elements 4 exhibit a higher stiffness than in the stiffness-reducing sections 7. This allows for a defined and well-controlled deflection of the displacement elements 4, since, for example, additional vibration modes or a reduced natural frequency due to excessive flexibility of the displacement element 4 can be avoided.

[0063] As in Fig. As can be seen in Figure 5, a block-shaped flywheel element 10 is arranged in each of the stiffening sections 9, with which a targeted increase in deflection can be achieved. The flywheel elements 10 can, in particular, extend over the entire height c of the displacement elements 4. The flywheel elements 10 can, for example, form a horizontal thickening structure of the displacement elements 4.

[0064] Fig. Figure 6 shows a top view of a microelectromechanical component 1 according to a third embodiment with displacer elements 4 clamped on both sides in a deflected state. As can be seen from the Fig. As can be seen in section 6, the stiffness reduction section 7 of the displacement elements 4 connects to the first mounting section 5 and the second mounting section 6, so that the deflection of the displacement elements 4 away from the substrate frame 2a can be further increased. The stiffness reduction section 7 is arranged between the first mounting section 5 and the second mounting section 6. Fig. Figure 6 further shows that stiffening sections 9 are formed approximately midway between the mounting sections 5, 6 of the displacement elements 4. In these stiffening sections, the displacement elements 4 exhibit a higher stiffness than in the stiffness-reducing sections 7, thereby enabling controlled deflection of the displacement elements 4. Several flywheel elements 10, designed as transverse struts, are arranged in each of the stiffening sections 9. Their inertial mass contributes to amplifying the deflection.

[0065] In Fig. Figure 7 shows a top view of a microelectromechanical component 1 according to a fourth embodiment with displacer elements 4 in a rest state. Fig. Figure 7 shows that a substrate 2 with a crystal orientation different from that described above was chosen for forming the substrate frame 2a and the displacement elements 7. Here, orthogonal structures of the microelectromechanical component 1 can be aligned along an eighth crystal orientation K4' along the (110) crystal plane and along a seventh crystal orientation K4 along the (110) crystal plane. As shown in Fig. As can be seen in Figure 7, the first fastening sections 5 and the second fastening sections 6 can be angled to a principal extension direction h of the displacer elements 4 and to the substrate frame 2a, such that the first and second fastening sections 5, 6 exhibit a first crystal orientation K1 along the (100)-crystal plane due to the angle. In this way, the first fastening sections 5 and the second fastening sections 6 each form stiffness-reducing sections 7, which have a reduced stiffness compared to a respective stiffening section 9 running essentially straight between the first frame part 2a-I and the second frame part 2a-II of the substrate frame 2a.With such stiffness-reduced fastening sections 5, 6, a flexible clamping of the displacement elements 4 can be achieved, which can be associated with a significantly reduced longitudinal stiffness, pronounced deflection capability and higher robustness of the displacement elements 4. As shown by the . Fig. As can be seen in Figure 7, the stiffening section 9 of the displacement elements 4 connects to the first mounting section 5 and the second mounting section 6. The stiffening section 9 is positioned between the first mounting section 5 and the second mounting section 6. This allows for increased stability of the displacement elements 4 in their mid-range of deflection, thus enabling well-controlled deflections. The angles in the mounting sections 5 and 6 are as shown in Figure 7. Fig. 7 are clearly arranged in a rotationally symmetrical manner relative to each other.

[0066] In Fig. Figure 8 shows a top view of a microelectromechanical component 1 according to a fourth embodiment with displacer elements 4 in a rest state. As in Fig. As indicated in Figure 8, orthogonal structures of the microelectromechanical device 1 can be aligned along the first crystal orientation K1 along the (100) crystal plane and along a third crystal orientation K2 along the (010) crystal plane. Fig. As can be seen in Figure 8, the first fastening sections 5 and the second fastening sections 6 are angled to a principal extension direction h of the displacement elements 4, while stiffness-reducing sections 7 between the fastening sections 5, 6 run along the principal extension direction h of the displacement elements 4. Due to the angling of the fastening sections 5, 6, they exhibit a crystal orientation that differs from the first crystal orientation K1, specifically an eighth crystal orientation K4' along the (110) crystal plane. This differing crystal orientation results in increased stiffness in the first and second fastening sections 5, 6 compared to the stiffness-reducing section 7, so that the first and second fastening sections 5, 6 can be considered stiffening sections 9. The angling in the fastening sections 5, 6 is as shown in Figure 8. Fig. 8 are clearly arranged axially symmetrically to each other. As further shown by the Fig. As can be seen in Figure 8, the stiffness reduction section 7 of the displacement elements 4 connects to the first mounting section 5 and the second mounting section 6. The stiffness reduction section 7 is positioned between the first mounting section 5 and the second mounting section 6. This allows for stable clamping even with large deflections of the displacement elements 4.

[0067] The Fig. Figure 9 shows an isolated perspective partial view of a displacement element 4 of a microelectromechanical component 1 according to a first embodiment. As in Fig. As can be seen in Figure 9, the first fastening section 5 has an oblique angle relative to the substrate frame 2a, allowing the displacer element 4 to transition into the substrate frame 2a. This enables a mechanically stress-free transition of the displacer element 4 into the substrate frame 2a. The first fastening section 5 has a transition surface 12 that exhibits a seventh crystal orientation K4 along the (110) crystal plane. Due to the differing crystal orientation, the first fastening section 5 has increased stiffness compared to the stiffness-reducing section 7, so the first fastening section 5 can be considered a stiffening section 9. A principal extension plane H2 of the stiffening section 9 can, as described above, have a seventh crystal orientation K4 along the (110) crystal plane.The formation of stress concentrations can be specifically avoided by this type of continuous transition in the first fastening section 5. This allows for larger deflections of the displacement element without compromising the robustness of the displacement elements in the event of overload.

[0068] Fig. Figure 10 shows an isolated perspective partial view of a displacement element 4 of a microelectromechanical component 1 according to a second embodiment. It can be seen that the mounting section 5 is designed as a bifurcation section 11, i.e., it has a fork. A bifurcation section 11 results in reduced bending stiffness, so the mounting section 5 can be considered a stiffness-reducing section 7, thus enabling flexible clamping of the displacement element 4 through a simple geometric adjustment.

[0069] Fig. Figure 11 shows an isolated perspective partial view of a displacement element 4 of a microelectromechanical component 1 according to a second embodiment. As in Fig. As can be seen in Figure 11, the first fastening section 5 has a curved profile, with which the displacement element 4 transitions into the substrate frame 2a. This effectively prevents mechanical stress concentrations in the displacement element 4, particularly in its transition area to the substrate frame 2a. The radius of curvature of the first fastening section 5 can be at least 5 µm, enabling a particularly smooth and gradual transition that contributes to a reduction in mechanical stresses.

[0070] In the Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17, Fig. 18 to Fig. Figure 19, which illustrates further embodiments of a microelectromechanical component 1, shows that the first mounting section 5 and the second mounting section 6 are each designed as bifurcation sections 11. A bifurcation section 11 results in reduced stiffness, so the first mounting sections 5 and the second mounting sections 6 can be considered stiffness-reducing sections 7. Furthermore, according to the Fig. 12 to 17b at least one further bifurcation section 11 is arranged as a stiffness-reducing section 11 between the first and second fastening sections 5, 6. Accordingly, the displacement elements 7 have several bifurcation sections 11, thereby achieving a targeted reduction in stiffness with precise control of the deflection behavior of the displacement elements 4.

[0071] In Fig. Figure 12 illustrates a displacer element 4 of a microelectromechanical component 1, mounted on both sides and in a rest state, according to a sixth embodiment. The bifurcation sections 11 in the region of the first and second mounting sections 5, 6 are fork-shaped, while a bifurcation section 11 between the first and second mounting sections 5, 6 has a polygonal outer contour, which here is designed as a diamond-shaped outer contour. This provides simple and robust design options for the bifurcation sections 11.

[0072] In Fig. Figure 13 illustrates a displacer element 4 of a microelectromechanical component 1, mounted on both sides and in a rest state, according to a seventh embodiment. The bifurcation sections 11 of the displacer element 4 shown here have a polygonal outer contour, which in this case is designed as a hexagonal outer contour in the form of a constricted rectangle. This provides bifurcation sections 11 with comparatively long legs, which can cause a significant local reduction in stiffness in the displacer element 4.

[0073] In Fig. Figure 14 illustrates a displacer element 4 of a microelectromechanical component 1, mounted on both sides and in a resting state, according to an eighth embodiment. The bifurcation sections 11 of the displacer element 4 shown here have a polygonal outer contour, which in this case is designed as a hexagonal outer contour. This provides bifurcation sections 11 with comparatively long legs, which can cause a significant local reduction in stiffness in the displacer element 4.

[0074] In Fig. Figure 15 illustrates a displacer element 4 of a microelectromechanical component 1, mounted on both sides and in a resting state, according to a ninth embodiment. The bifurcation sections 11 of the displacer element 4 shown here have a round outer contour, which in this case is designed as a circular outer contour. This provides bifurcation sections 11 with favorable force flow guidance and a minimization of mechanical stress peaks.

[0075] In Fig. Figure 16 illustrates a displacer element 4 of a microelectromechanical component 1, mounted on both sides and in a rest state, according to a tenth embodiment. Fig. Figure 16 shows that the displacement element 4 has several successive quadrilateral bifurcation sections 11 which together form a meandering outer contour with a triangular base shape, thereby achieving a high degree of flexibility in the displacement element 4. Furthermore, the embodiment according to the tenth embodiment is a displacement element 4 in which several successive bifurcation sections 11 extend over the entire displacement element 4 to further reduce its longitudinal stiffness.

[0076] The Fig. 17a and Fig. Figure 17b shows, for comparison, the displacement element 4 of the microelectromechanical component 1 according to the sixth embodiment in a rest state and a deflected state. It can be seen that in a deflected state, an outer leg of the bifurcation section 11 is stretched on a first element side of the displacement element 4, and an inner leg of the bifurcation section 11 is compressed on a second element side of the displacement element 4. This behavior of the bifurcation section 11 can, for example, support an elastic recovery of the displacement element 4.

[0077] The Fig. 18, Fig. 19 to Fig. Figures 20 each show a top view of a displacer element 4 of a microelectromechanical device 1 in a rest state, mounted on two sides, according to the eleventh, twelfth, and thirteenth embodiments. In these embodiments, the bifurcation sections 11 shown are elongated, successive bifurcation sections 11 that extend substantially over the entire displacement element 4 and thus allow a high degree of deflection of the displacement element 4 along its entire length between the mounting sections 5 and 6. The transitions between the bifurcation sections 11, as well as the mounting sections 5 and 6, can form mechanical hinge structures to improve the mobility of the displacement element 4.

[0078] The Fig. Figure 21 shows an isolated perspective view of a displacement element 4 of a microelectromechanical component 1 with electrode devices 13 extending transversely to the displacement element 4 at its vertical ends for deflecting the displacement element 4. As can be seen, these can span the first mounting section 5 and the second mounting section 6, thus enabling a deflection of the displacement element 4 that can be controlled over a wide range. Furthermore, the Fig. 21 recognizable that a bifurcation section 11 of the displacement element 4 can be formed over its entire height extension.

[0079] In Fig.Figure 22 shows a simplified schematic diagram of a microelectromechanical device 19 with a microelectromechanical component 1. The microelectromechanical device 19 can, for example, be configured as a microelectromechanical loudspeaker. The microelectromechanical component 1 can therefore be configured as a sound transducer component. The microelectromechanical device 19 has a signal processing unit 20, for example, configured as an ASIC, for applying, receiving, and / or processing signals from the microelectromechanical component 1. This signal processing unit is connected to the microelectromechanical component 1 via a signal connection 21, for example, one or more wire bonds. The microelectromechanical device 19 enables high displacement power, in particular high sound pressure levels with high signal quality, while maintaining a small size for the microelectromechanical component 1.

Claims

[1] Microelectromechanical device (1) with a substrate (2) which has a substrate recess (3) bounded by a substrate frame (2a) and at least one displacement element (4) extending in the substrate recess (3), which is anchored to a first frame part (2a-I) of the substrate frame (2a) by a first fastening section (5) and is deflectable at least in part, wherein the at least one displacement element (4) has a stiffness reduction section (7). [2] Microelectromechanical device (1) according to claim 1, wherein at least one displacer element (4) of the microelectromechanical device (1) has a second fastening section (6) with which the displacer element (4) is attached to a second frame part (2a-II) of the substrate frame (2a). [3] Microelectromechanical component (1) according to claim 1 or 2, wherein at least one displacer element (4) of the microelectromechanical component (1) has a free end (8) which faces a second frame part (2a-II) of the substrate frame (2a). [4] Microelectromechanical component (1) according to one of the preceding claims, wherein the stiffness reduction section (7) connects to the first mounting section (5) and / or to the second mounting section (6) and / or wherein the stiffness reduction section (7) is arranged between the first mounting section (5) and the second mounting section (6). [5] Microelectromechanical component (1) according to one of the preceding claims, wherein the first fastening section (5) and / or the second fastening section (6) extend at an angle to a principal extension direction (h) of the displacement element (4) and / or wherein the stiffness reduction section (7) extends at an angle to a principal extension direction (h) of the displacement element (4). [6] Microelectromechanical component (1) according to one of the preceding claims, wherein the first fastening section (5) and / or the second fastening section (6) is designed as a stiffness reduction section (7). [7] Microelectromechanical device (1) according to one of the preceding claims, wherein the displacer element (4) has a stiffening section (9) which has a higher stiffness than the stiffness reduction section (7). [8] Microelectromechanical component (1) according to claim 7, wherein the first fastening section (5) and / or the second fastening section (6) is designed as a stiffening section (9). [9] Microelectromechanical component according to claim 7, wherein the stiffening section (9) connects to the first mounting section (5) or to the second mounting section (6) and / or wherein the stiffening section (9) is arranged between the first mounting section (5) and the second mounting section (6). [10] Microelectromechanical component (1) according to one of claims 7 to 9, wherein the stiffening section (9) comprises a flywheel element (10). [11] Microelectromechanical device (1) according to one of the preceding claims, wherein the substrate (2) and the displacer element (4) are monocrystalline and wherein the stiffness reduction section (7) along a principal extension plane (H) of the displacer element (4) has a first crystal orientation (K1) in a range of + / -30° around the (100) crystal plane. [12] Microelectromechanical device (1) according to claim 11, wherein the stiffness reduction section (7) has a first crystal orientation (K1) along the main extension plane (H) of the displacer element (4) along the (100) crystal plane. [13] Microelectromechanical device (1) according to claim 11 or 12, wherein the substrate (2) has a substrate surface (2b) with a fifth crystal orientation (K3) along the (001) crystal plane. [14] Microelectromechanical device (1) according to one of the preceding claims, wherein the stiffening section (9) has a crystal orientation (K1', K2, K2', K3, K3', K4) that differs from the first crystal orientation (K1) along a principal extension plane (H2) of the stiffening section (9). [15] Microelectromechanical device (1) according to one of the preceding claims, wherein the displacer element (4) transitions into the substrate frame (2a) with a third crystal orientation (K2) along the (010) crystal plane and / or with a fourth crystal orientation (K2') along the (010) crystal plane. [16] Microelectromechanical device (1) according to one of the preceding claims, wherein the displacer element (4) in the first mounting section (5) and / or in the second mounting section (6) has a crystal orientation (K1', K2, K2', K3, K3', K4) that differs from the first crystal orientation (K1) along the main extension plane (H) of the displacer element (4). [17] Microelectromechanical device (1) according to one of the preceding claims, wherein the stiffness reduction section (7) is designed as a bifurcation section (11). [18] Microelectromechanical device (1) according to claim 17, wherein the displacer element (4) has several bifurcation sections (11). [19] Microelectromechanical component (1) according to claim 17 or 18, wherein the first fastening section (5) and / or the second fastening section (6) is designed as a bifurcation section (11). [20] Microelectromechanical component (1) according to one of claims 17 to 19, wherein at least one bifurcation section (11) of the displacer element (4) is arranged between the first mounting section (5) and the second mounting section (6). [21] Microelectromechanical device (1) according to one of claims 17 to 20, wherein at least one bifurcation section (11) of the displacer element (4) has a polygonal outer contour. [22] Microelectromechanical device (1) according to one of claims 17 to 21, wherein at least one bifurcation section (11) of the displacer element (4) has a rounded outer contour. [23] Microelectromechanical device (1) according to one of claims 17 to 22, wherein several successive bifurcation sections (11) together form a meandering outer contour. [24] Microelectromechanical device (1) according to one of claims 17 to 23, wherein the bifurcation section (11) or several successive bifurcation sections (11) extend over the entire displacement element (4). [25] Microelectromechanical component (1) according to one of the preceding claims, wherein the first fastening section (5) and / or the second fastening section (6) has a stepped profile, an angled profile to the substrate frame (2a) or a curved profile with which the displacer element (4) transitions into the substrate frame (2a). [26] Microelectromechanical component (1) according to claim 25, wherein the first fastening section (5) and / or the second fastening section (6) has a curved profile with a radius of curvature of at least 5 µm. [27] Microelectromechanical device (1) according to claim 25 or 26, wherein the first fastening section (5) and / or the second fastening section (6) has an obliquely angled course to the substrate frame (2a) with a transition surface (12) having a seventh crystal orientation (K4) along the (110) crystal plane. [28] Microelectromechanical component (1) according to one of the preceding claims, wherein an electrode device (13) arranged transversely to the displacement element (4) at its height end is provided for deflecting the displacement element (4). [29] Microelectromechanical component (1) according to claim 28, wherein the electrode device (13) spans the first mounting section (5) or the second mounting section (6). [30] Microelectromechanical component (18) comprising a microelectromechanical component (1) according to one of the preceding claims, a base substrate (16) at least partially covering the substrate recess (3), a cover substrate (15) at least partially covering the substrate recess (3), at least one fluid opening (17) in the base substrate (16) and / or in the cover substrate (15) and with a drive device (14) for generating a deflection of the displacement element (4) and / or with a detection device for detecting a deflection of the displacement element (4). [31] Microelectromechanical component (18) according to claim 30, wherein the microelectromechanical component (18) is configured as a sound transducer component. [32] Microelectromechanical device (19) comprising a microelectromechanical component (18) according to claim 30 or 31 and comprising a signal processing unit (20) for applying, receiving and / or processing signals of the microelectromechanical component (18). [33] Microelectromechanical device (19) according to claim 32, wherein the microelectromechanical device (19) is designed as a microelectromechanical loudspeaker.

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