Micro-electromechanical device and method for producing a micro-electromechanical device

Abstract

The invention relates to a micro-electromechanical device (1) with a MEMS component (2) and an ASIC component (3), which are mounted on a carrier structure (4) of the device (1), wherein the carrier structure (4) has an access opening (5) adjacent to the MEMS component (2), and wherein the MEMS component (2) is mounted on a first surface (6a) of the carrier structure (4) and the ASIC component (3) is mounted on a second surface (6b) of the carrier structure (4), wherein the second surface (6b) is oriented substantially orthogonally to the first surface (6a) of the carrier structure (4). The invention also relates to a method (100) for producing such a micro-electromechanical device (1).

Description

[0001] Description

[0002] title

[0003] Microelectromechanical device and method for producing a microelectromechanical device

[0004] The invention relates to a microelectromechanical device and a method for producing a microelectromechanical device.

[0005] State of the art

[0006] Microelectromechanical devices, also called MEMS devices, and methods for their manufacture are known from the prior art.

[0007] US 9407 997 B2 describes a MEMS device comprising a base and a cap element, between which a MEMS microphone component is arranged, and an integrated circuit in the base element. A sound opening of the MEMS device extends through the base element and the integrated circuit.

[0008] US 2015 / 0 195659 A1 relates to a MEMS microphone comprising a base and cap element, as well as an interposer, which enclose a cavity containing a MEMS structure and an ASIC. An electrical connection is established between the base and cap elements via the interposer.

[0009] CN 2 11 429 522 U discloses a MEMS microphone with a housing in which a first circuit board and a second circuit board oriented perpendicular to the first circuit board are arranged, which can be optionally connected to a MEMS chip or an ASIC chip. CN 2 10 927 973 II discloses an acoustic MEMS sensor with a first and second substrate, wherein a MEMS chip is arranged on the first substrate and an ASIC chip electrically connected thereto is integrated into the first substrate.

[0010] Disclosure of the invention

[0011] According to the features of independent claim 1, a microelectromechanical device is proposed comprising a MEMS component and an ASIC component which are attached to a support structure of the device, wherein the support structure has an access opening adjacent to the MEMS component, and wherein the MEMS component is attached to a first surface of the support structure and the ASIC component is attached to a second surface of the support structure, wherein the second surface is oriented substantially orthogonal to the first surface of the support structure.

[0012] This provides a compact microelectromechanical device in which the available installation space of the device, which is only limited by the access opening, is better utilized through an orthogonal alignment of the MEMS and ASIC components. The reduced space requirement of the components increases design freedom during device manufacture, as the components can be arranged at a freely selectable distance from one another. In particular, the ASIC component can be arranged at a distance from the access opening. Furthermore, the components can be clearly separated and delimited from one another, so that mutual mechanical or electrical interference can be reduced or eliminated. The proposed arrangement avoids a stacked arrangement of the MEMS and ASIC components.

[0013] A microelectromechanical device can be a device with microstructures and electromechanical transducers, which can be configured, for example, to interact with the device's environment. The microstructures can, in particular, be produced using semiconductor technology and, for example, have mechanical, optical, physical, and / or chemical components and / or functions. Such devices can be used, among other things, as miniaturized sensors or actuators. For example, the microstructures can be configured to detect or generate fluid flows or pressures. In particular, the microstructures can be suitable for detecting or generating sound pressure to form an acoustic microelectromechanical device.

[0014] The MEMS component can represent a component of the microelectromechanical device that has at least one movable microstructure for interacting with the device's environment. The movable microstructure, for example, an elastically deflectable membrane, can define a MEMS functional plane of the MEMS component. The MEMS functional plane can, in particular, run parallel to the first surface of the support structure on which the MEMS component is arranged. The MEMS component can have one or more MEMS functional planes, which can, for example, be formed by one or more elastic membranes.

[0015] The ASIC component can represent a component of the microelectromechanical device that forms a signal processing unit for applying and processing signals from the microelectromechanical device, for example, for controlling the MEMS component or for evaluating signals from the MEMS component. The abbreviation ASIC stands for a so-called application-specific integrated circuit, which represents an electronic circuit implemented as an integrated circuit. Accordingly, the ASIC component has at least one circuit structure that can define an ASIC functional level of the ASIC component. The ASIC functional level can run parallel to the second surface of the carrier structure on which the ASIC component is arranged. The ASIC component can have one or more ASIC functional levels, which can be formed, for example, by circuit levels.By arranging the MEMS and ASIC components on surfaces of the support structure that are aligned perpendicular to each other, the aforementioned functional planes of the components can also be aligned essentially perpendicular to each other, so that, for example, the circuit structure of the ASIC component extends along a different spatial axis than the movable microstructure of the MEMS component. This allows for improved separation of the functional planes from one another while simultaneously maintaining a compact device design. In particular, an undisturbed interaction of the microstructure of the MEMS component with the environment via the access opening of the support structure can be supported.

[0016] The support structure can be an electromechanical component of the device, which can support and fix the MEMS and ASIC components in space, as well as include electrical connection and contacting structures to make the components electrically contactable with one another and with the device as a whole from the outside. The support structure has a first surface on which the MEMS component is arranged, and a second surface on which the ASIC component is arranged, wherein the first and second surfaces are aligned substantially orthogonally to one another. In this context, an orthogonal alignment to one another means that the spatial axes or spatial planes in which the first and second surfaces extend intersect one another at a perpendicular angle.The first and second surfaces therefore do not necessarily have to be directly adjacent to one another, but can be conceptually extended in the directions of their planar extension to determine their alignment. Accordingly, for example, a lateral offset between the MEMS component and the ASIC component can be provided. A lateral offset between the MEMS component and the ASIC component can, in principle, be freely selected within the framework of technical conditions such as required lateral distances and wire bridge lengths. The term "lateral" can refer to a spatial direction parallel to the planar extension of the first or second surface.Attaching the components to the surfaces particularly means a permanent fixation, which may not be removable without destruction and may be based, for example, on a material-to-material joining process or an additive manufacturing process.

[0017] The support structure has an access opening that enables interaction of the MEMS component, in particular its movable microstructure, with the environment of the device. The MEMS component can have an active surface in the region of the access opening that is configured to detect or influence ambient conditions of the device. The access opening can extend through the first surface, so that the MEMS component can be attached to the first surface in a region adjacent to the access opening. The MEMS component can therefore span the access opening in a bridge-like manner. Depending on the embodiment, the access opening can form, for example, a pressure access or a sound opening for sound entry or exit.According to an advantageous embodiment, the MEMS component is also designed to be exposed on a side opposite the access opening, for example to achieve improved interaction of the MEMS component with the environment or to enable pressure equalization with the environment. An exposed design can be provided, for example, if the carrier structure forms a predominantly planar carrier structure on which the MEMS component is arranged. For example, a MEMS substrate and / or an ASIC substrate can form a planar carrier structure, since such substrates can have a predominantly flat extension. If the carrier structure is designed as a carrier structure surrounding the MEMS component on several sides, the carrier structure can, for example, have two opposing access openings between which the MEMS component is arranged.For example, in an acoustic microelectromechanical device, the access openings can form a front volume and a rear volume.

[0018] According to one embodiment, the support structure can comprise a MEMS substrate to which the MEMS component is attached, and the support structure can comprise an ASIC substrate arranged substantially orthogonally to the MEMS substrate, to which the ASIC component is attached. This makes it possible to provide a simple and cost-effective support structure which, through the MEMS substrate and the ASIC substrate, provides suitable first and second surfaces for attaching the MEMS component and the ASIC component. Furthermore, such a support structure enables a space-saving, compact design of the device. The ASIC substrate can be attached to the MEMS substrate in its orthogonal orientation, for example, it can be materially connected to a surface of the MEMS substrate on an end face of the ASIC substrate, which surface forms the first surface of the MEMS substrate or runs parallel to it.The MEMS substrate and / or the ASIC substrate can be designed as printed circuit boards, for example as two-layer printed circuit boards with top and bottom metallization, although, depending on the embodiment, multilayer printed circuit boards with more than two layers can also be advantageous. The MEMS and ASIC components can be arranged on the printed circuit boards as surface-mounted devices (SMDs). The MEMS substrate and / or the ASIC substrate can have conductor tracks parallel and / or orthogonal to a substrate surface of the respective substrate. Furthermore, it is conceivable for the MEMS substrate and / or the ASIC substrate to be provided with edge plating to enable contacting at an end face of the substrate.

[0019] According to an alternative embodiment, the carrier structure can be an MID circuit carrier. The abbreviation MID stands for Molded Interconnect Device and refers to an injection-molded three-dimensional circuit carrier. The basic geometric shape of the MID is produced by plastic injection molding and then provided with electrically conductive structures using special processes, such as laser structuring or laser activation followed by metallization. For example, three-dimensional plastic components can be provided with integrated conductor tracks, wire bonding, or solder pads, which enable an electrical connection between components arranged on the circuit carrier and external contacting of the circuit carrier.A carrier structure formed by a MlD circuit carrier can provide a compact microelectromechanical device with high mechanical protection for the components attached to the carrier structure. A MlD circuit carrier offers a high degree of design and shape freedom with regard to the mechanical and electrical structures provided on the carrier structure and their relative arrangement. For example, three-dimensional conductor track layouts can be easily implemented, or spatial recesses, grooves, cavities, and receptacles for the components and other components of the device, such as protective membranes, can be implemented on the MlD circuit carrier. Accordingly, the shape of the device can be individually adapted to specified product or process requirements for further processing.

[0020] According to an alternative embodiment, the carrier structure can be an additively manufactured layered circuit carrier. Such a carrier structure can be a layer-by-layer manufactured carrier structure that is created during the manufacture of the microelectromechanical device. This allows the carrier structure to be individually adapted to the components and predefined mechanical and electrical requirements of the device. The carrier structure can comprise additively manufactured mechanical structures and optionally additively manufactured electrical structures. For example, the carrier structure can comprise complex three-dimensional conductor track structures produced layer by layer. Furthermore, a protective membrane, for example, can be integrated into the layer structure. The MEMS component can be embedded in the layered circuit carrier so that it is reliably sealed by the produced layers.This can, for example, lead to improved acoustic properties for an acoustic MEMS component, for example by avoiding acoustic leakage paths.

[0021] According to one embodiment, the carrier structure can have an electrical contacting structure on a carrier structure side facing away from the MEMS component and the ASIC component. The carrier structure side can in particular form an outer side of the carrier structure, for example a bottom side of the carrier structure, on which the access opening can be arranged, or a top side opposite the bottom side of the carrier structure. This allows the microelectromechanical device to be contacted from the outside, for example to be connected to a circuit board or an electrical device. The electrical contacting structure can be used, for example, to control the microelectromechanical device or to detect signals, for example measurement signals from the microelectromechanical device.The electrical contacting structure can be connected to the MEMS component and / or the ASIC component via electrical conduction paths that run through the carrier structure. For example, conductor tracks can run between the top and bottom metallization in a MEMS substrate of the carrier structure designed as a printed circuit board. For example, conductor tracks with three-dimensional path paths can run through a carrier structure designed as a MID circuit carrier. This allows electrical connections to be established between the components and the electrical contacting structure.

[0022] According to one embodiment, the MEMS component and the ASIC component can be electrically connected to one another by at least one wire bridge contact. Such wire bridge contacts can be produced simply and cost-effectively using wire bonding methods and establish a reliable electrical connection between the MEMS component and the ASIC component. Furthermore, it is conceivable to use wire bridge contacts to establish an electrical connection between the MEMS component and / or the ASIC component and a connection structure of the carrier structure, for example, with a soldering or bonding pad of a MEMS substrate or with a connection structure of a MID circuit carrier, wherein the aforementioned connection structures can in turn be electrically connected to an electrical contacting structure of the carrier structure.Depending on the embodiment, the MEMS component and the ASIC component can be electrically connected to one another directly by wire bridge contacts or indirectly via the carrier structure, for example by a wire bridge contact between the MEMS component or ASIC component and a carrier structure designed as a MI D circuit carrier for indirectly contacting the other component via the wire bridge contact and the carrier structure.

[0023] According to one embodiment, the MEMS component and / or the ASIC component can be connected to the support structure by means of an adhesive bond. An adhesive bond achieves advantageous stress decoupling between the MEMS and / or ASIC component and the support structure. Furthermore, the adhesive bond enables a tight, in particular gas-tight, seal between the components and the support structure, which, for example, improves the acoustic properties of the microelectromechanical device with regard to an acoustic MEMS component, such as a loudspeaker or a microphone. Furthermore, the microelectromechanical device is easy to manufacture if the MEMS component and / or the ASIC component is connected to the support structure by means of an adhesive bond. A liquid adhesive, which may comprise, for example, an epoxy or silicone material, can be used as the adhesive.Depending on the design and connection point of the device, an electrically conductive or electrically non-conductive adhesive can be used. Adhesive bonds can generally be formed, for example, between the MEMS component and a MEMS substrate, the ASIC component and an ASIC substrate, between a MEMS substrate and an ASIC substrate, between the MEMS component and a MID circuit carrier, and between the ASIC component and a MID circuit carrier.

[0024] According to one embodiment, the MEMS component and / or the ASIC component can be connected to the carrier structure by means of a solder connection. To create the solder connection, for example, special solder deposits, also called solder balls, can be placed at the connection point before the joining partners are arranged on top of one another. The components can, for example, first be provided with the solder deposits and then applied to the intended surface using flip-chip technology. An electronic solder, for example a silver-copper-tin solder, can be used as the solder material. The solder connection is electrically conductive and can therefore be used as an electrical connection between the joining partners, so that an additional wire bridge contact is not required. The solder connection thus mechanically and electrically connects the component to the substrate.Furthermore, the surface tension of solder balls can be advantageously utilized during device manufacturing, as it exerts a self-centering effect between the structures to be joined. Furthermore, a soldered joint requires less lateral space at the joining surface than an adhesive joint, allowing for tighter manufacturing tolerances and reduced clearances between the component structures. According to a further development of the described embodiment, the soldered joint can be sealed and mechanically stabilized with an adhesive or an underfill.In principle, solder connections can be present, for example, between the MEMS component and a MEMS substrate, the ASIC component and an ASIC substrate, between a MEMS substrate and an ASIC substrate, between the MEMS component and a MIDI circuit carrier, and between the ASIC component and a MIDI circuit carrier. Furthermore, it is conceivable for the microelectromechanical device to have an adhesive connection at at least one of the aforementioned connection points and a solder connection at at least one other of the aforementioned connection points, so that the respective advantages of the connection types can be individually utilized and adapted to different connection points.

[0025] According to one embodiment, the support structure can have at least one recess into which the MEMS component and / or the ASIC component is immersed, at least in part. This allows the recess to form a receptacle for the MEMS component and / or the ASIC component, thus achieving improved mechanical protection and facilitating connection of the component to the support structure in the manner of a plug-in connection. Furthermore, this allows the system height of the ASIC system comprising the ASIC substrate and the ASIC component to be reduced.The recess can, for example, be introduced into a MEMS substrate of the carrier structure, for example, by milling. The MEMS substrate can be designed as a multilayer printed circuit board in order to be able to provide a recess with an electrically contactable surface, and can also have a predefined minimum thickness to ensure sufficient mechanical stability, for example against torsion and warping. The recess can, for example, be formed as a geometric recess on a MID circuit carrier using a suitable injection mold. The recess can, for example, be introduced into the layer structure of an additively manufactured layered circuit carrier as a layer recess or intermediate layer structuring.According to a further development of the described embodiment, the recess can be at least partially filled, for example with an adhesive or an underfill, after the component has been accommodated in order to achieve greater mechanical stability of the component. For example, an ASIC substrate with a connected ASIC component can be immersed at least partially into a recess of a MEMS substrate and fixed in the recess by an underfill or an adhesive. Alternatively, the ASIC substrate with the ASIC component can be mechanically stiffened, for example by a polymer encapsulation. Furthermore, it is conceivable for the carrier structure to have further recesses for mechanical or electrical structures other than the MEMS or ASIC component.

[0026] According to one embodiment, the ASIC component can have a width that essentially corresponds to the height of the MEMS component. This makes it possible to provide a flat, compact microelectromechanical device even when the components are arranged essentially orthogonally to one another. Due to the perpendicular alignment of the components to one another, the components according to the described embodiment can have a comparable height relative to the same spatial axis. This allows an electrical connection between the ASIC component and the MEMS component to be formed reliably and easily, for example, by a wire bridge contact between the components. Furthermore, the support structure and any additionally provided housing of the microelectromechanical device can be designed compactly and with advantageous use of installation space.The height of the MEMS device may be an extension of the MEMS device perpendicular to the first surface to which the MEMS device is attached. The width of the ASIC device may be an extension of the ASIC device parallel to the second surface to which the ASIC device is attached.

[0027] According to one embodiment, a protective membrane can be arranged on the support structure. A protective membrane can, for example, be a membrane for protecting the device from particles or moisture and can be arranged, for example, on a top and / or bottom side of the support structure. According to a further development, the protective membrane can be arranged in a depression in the support structure. This allows the protective membrane to be arranged in a mechanically protected manner and also to be attached more easily and securely.

[0028] According to one embodiment, the device can be designed as a sound transducer. The proposed microelectromechanical device can provide a compact, robust, and powerful sound transducer. A sound transducer can be, for example, a microphone or a loudspeaker. The MEMS component can be designed as an acoustic MEMS component for a sound transducer and, for example, have at least one deflectable membrane as a microstructure for detecting or generating sound pressure. In a sound transducer, the access opening can, for example, form a sound opening to form a front or rear volume of the acoustic MEMS component.

[0029] In principle, however, the device can also be designed as a non-acoustic sensor or actuator. For example, the device can also be designed as an environmental sensor, such as a pressure sensor or a humidity sensor, or as a microvalve or micropump for microfluidic applications.

[0030] Depending on the selected embodiment, the microelectromechanical device may have a housing structure to protect the device from mechanical impacts and undesirable environmental influences, such as particle and liquid ingress. A housing structure may, for example, be a cap structure covering the MEMS component and the ASIC component, or an additively produced layer structure accommodating the components, which, for example, enables essentially complete encapsulation of the ASIC component.

[0031] The invention also relates to a method for producing a microelectromechanical device, comprising the steps:

[0032] - Providing a MEMS component and an ASIC component;

[0033] - Providing or creating a support structure with an access opening; - Attaching the MEMS component to a first surface of the support structure such that the MEMS component spans the access opening; and

[0034] - Attaching the ASIC component to a second surface of the support structure, wherein the second surface is oriented substantially orthogonally to the first surface of the support structure.

[0035] The proposed method allows for the simple production of a compact microelectromechanical device. The available device space, which is limited by the access opening, is better utilized through an orthogonal alignment of the MEMS and ASIC components. Due to the reduced space required by the components, the method offers a high degree of design freedom, as the components can be arranged at a freely selectable distance from one another. In particular, the ASIC component can be arranged at a distance from the access opening. Furthermore, the components can be clearly separated and delimited from one another, thus reducing or eliminating mutual mechanical or electrical interference during device operation.

[0036] According to one embodiment, a MEMS substrate and an ASIC substrate can be provided and connected to one another as the support structure, wherein the ASIC substrate is arranged substantially orthogonally to the MEMS substrate. This allows the use of a simple and cost-effective support structure which, through the MEMS substrate and the ASIC substrate, provides suitable first and second surfaces for attaching the MEMS component and the ASIC component. The ASIC substrate can be attached to the MEMS substrate in its orthogonal orientation, for example, it can be materially bonded to a surface of the MEMS substrate on an end face of the ASIC substrate, which surface forms the first surface of the MEMS substrate or runs parallel to it.The method can, for example, utilize chip-on-board technology, in which the MEMS component and the ASIC component are each attached to the MEMS substrate and ASIC substrate by direct assembly as SMD components. For example, the MEMS component can be bonded to the MEMS substrate and the ASIC component to the ASIC substrate, the MEMS substrate and the ASIC substrate with the bonded components can be positioned and connected to one another, and then the MEMS component and the ASIC component are electrically connected to one another via wire bridge contacts. Furthermore, an electrical contacting structure can be provided or created on a carrier structure side facing away from the MEMS component and the ASIC component, for example, an underside of the MEMS substrate.In addition, a recess can be introduced into the MEMS substrate, for example by milling, into which the ASIC component is embedded, at least in sections.

[0037] As an alternative to an adhesive bond between the components and the substrates, they can be attached to each other using a solder joint. For example, flip-chip technology can be used, in which solder deposits are applied to the contact pads of the components, the components are rotated around their axes, and placed on the respective substrate. The thus prepared unit, consisting of component and substrate, is heated so that the solder in the solder deposits melts and then solidifies again. The solder joint mechanically and electrically connects the component to the substrate. The solder joint can optionally be sealed and mechanically stabilized with an adhesive or underfill.

[0038] According to an alternative embodiment, a MID circuit carrier can be provided as the carrier structure. A carrier structure formed by a MID circuit carrier can provide a compact microelectromechanical device with high mechanical protection for the components attached to the carrier structure. A MID circuit carrier offers a high degree of design and shape freedom with regard to the mechanical and electrical structures provided on the carrier structure and their arrangement relative to one another. Depending on the embodiment, the MEMS component and / or the ASIC component can be attached to the MID circuit carrier, for example, by an adhesive bond and / or a solder bond, and optionally connected via a wire bridge contact.The MID circuit carrier can advantageously have a recess for the MEMS component and / or the ASIC component, into which the respective component can be embedded and, for example, secured to a bottom surface of the recess. Furthermore, an electrical contacting structure can be provided or created on a carrier structure side facing away from the MEMS component and the ASIC component, for example, a bottom or top side of the MID circuit carrier.

[0039] According to an alternative embodiment, the carrier structure can be produced as a layered circuit carrier using an additive manufacturing process. This allows the positioning of the components to be combined with the construction of a housing structure for the device. The carrier structure can therefore be produced layer by layer, and the MEMS component and the ASIC component can be integrated into the layers. For example, the components can each be placed on an already produced layer and then at least partially encased or covered by additional layers. Through additive manufacturing, the carrier structure can be individually adapted to the components and predefined mechanical and electrical requirements of the device. Furthermore, such a carrier structure can be used to easily and flexibly provide prototypes of the microelectromechanical device, for example for testing and demonstration purposes.By selecting a suitable additive manufacturing process, also known as 3D printing, it is possible to create mechanical and electrical structures with a high degree of design freedom during the additive manufacturing process to form the layered circuit carrier. For example, complex three-dimensional conductor tracks can be created layer by layer. This eliminates the need for additional wire bridge contacts and correspondingly provided wire bond pads on the device, thus eliminating the associated requirement to maintain minimum or maximum distances. Alternatively, the wire bridge contacts can be created directly using the additive manufacturing process, eliminating the need for a subsequent wire bonding process. Furthermore, the edge clearances to be considered in the area of ​​the corners and sides of the MEMS component can be reduced.Furthermore, the increased installation space of the carrier structure can be used to lay conductor tracks. Furthermore, a protective membrane, for example, can be integrated directly into the layered structure, eliminating the need for subsequent attachment. Furthermore, the layered circuit carrier can embed the MEMS component and thus reliably seal it, so that, for example, improved acoustic properties can be achieved for an acoustic MEMS component, for example, acoustic leakage paths can be avoided. Furthermore, a subsequent encapsulation process can be eliminated because the components are already enclosed directly in the layered structure during the manufacturing process. An electrical contacting structure can be provided or created on a side of the carrier structure facing away from the MEMS component and the ASIC component, for example, a bottom or top side of the layered circuit carrier.

[0040] In general, in the context of this application, the words “a / an”, unless expressly defined otherwise, are not to be understood as a number, but as an indefinite article with the literal meaning of “at least one”.

[0041] The invention permits various embodiments and is explained in more detail below using exemplary embodiments with the accompanying drawings. They show schematically:

[0042] Fig. 1 - a microelectromechanical device according to a first

[0043] Embodiment in a sectional view;

[0044] Fig. 2 - a microelectromechanical device according to a second

[0045] Embodiment in a sectional view;

[0046] Fig. 3 - a microelectromechanical device according to a third

[0047] Embodiment in a sectional view;

[0048] Fig. 4a-4b - Detailed views of a microelectromechanical device according to a fourth embodiment in a sectional view;

[0049] Fig. 5 - a detailed view of a microelectromechanical device according to a fifth embodiment in a sectional view; Fig. 6 - a microelectromechanical device according to a sixth

[0050] Embodiment in a sectional view;

[0051] Fig. 7 - a microelectromechanical device according to a seventh

[0052] Embodiment in a sectional view;

[0053] Fig. 8 - a microelectromechanical device according to an eighth

[0054] Embodiment in a sectional view;

[0055] Fig. 9 - a microelectromechanical device according to a ninth

[0056] Embodiment in a sectional view;

[0057] Fig. 10 - a microelectromechanical device according to a tenth

[0058] Embodiment in a sectional view;

[0059] Fig. 11 - a microelectromechanical device according to an eleventh

[0060] Embodiment in a sectional view;

[0061] Fig. 12 - a microelectromechanical device according to a twelfth

[0062] Embodiment in a sectional view;

[0063] Fig. 13 - a simplified flow diagram of a method for manufacturing a microelectromechanical device.

[0064] Fig. 1 schematically shows a microelectromechanical device 1 according to a first embodiment. The device 1 has a MEMS component 2 and an ASIC component 3. The MEMS component 2 and the ASIC component 3 are attached to a support structure 4 of the device 1. The support structure 4 has an access opening 5 adjacent to the MEMS component 2. The MEMS component 2 is attached to a first surface 6a of the support structure 4. The ASIC component 3 is attached to a second surface 6b of the support structure 4. The second surface 6b is aligned substantially orthogonal to the first surface 6a. The described microelectromechanical device 1 results in a compact device 1 with improved space utilization despite the reduced space available due to the existing access opening 5. As can be seen from Fig. 1, the MEMS component 2 spans the access opening 5 in a bridge-like manner.Through the access opening 5, microstructures of the MEMS component 2 (not shown in detail) can interact with the environment of the device 1, for example, as a movable membrane, experiencing a deflection due to ambient or sound pressure, which can be detected electrostatically, for example. Conversely, a movable membrane of the MEMS component 2 can be actively deflected by an applied signal, for example to generate a fluid or sound pressure. The device 1 can, for example, form an acoustic microelectromechanical device 1 in the form of a sound transducer such as a microphone or loudspeaker, or a pressure sensor, and the access opening 5 can, for example, represent a pressure access or a sound opening for sound entry and / or exit.The MEMS component 2 can have one or more active surfaces, which can be arranged, for example, on a side of the MEMS component 2 facing the access opening 5 and on a side of the MEMS component 2 opposite the aforementioned side. The MEMS component 2 is electrically connected to the ASIC component 3. The ASIC component 3 can, for example, be configured to apply and process signals from the MEMS component 2, for example, to control the microstructures of the MEMS component 2 or to forward measurement signals acquired by the microstructures to the ASIC component 3. The support structure 4 serves as a mechanical base for the MEMS component 2 and the ASIC component 3 and, depending on the embodiment, can provide an electrical connection between the MEMS component 2 and the ASIC component 3 and / or establish an external connection readiness of the device 1.

[0065] According to the embodiment shown in Fig. 1, the support structure 4 is a MEMS substrate 7 to which the MEMS component 2 is attached. An ASIC substrate 8, to which the ASIC component 3 is attached, is arranged substantially orthogonally to the MEMS substrate 7. This utilizes a simple and cost-effective support structure 4 and creates a flat device 1. The MEMS substrate 7 has a first surface 6a to which the MEMS component 2 is attached, and the ASIC substrate 8 has a second surface 6b to which the ASIC component 3 is attached. The ASIC substrate 8 is integrally connected at one of its end faces to the first surface 6a of the MEMS substrate 7 and is thereby attached to the MEMS substrate 7 in an orthogonal alignment. The MEMS substrate 7 and the ASIC substrate 8 can be arranged as shown in Fig.1 as two-layer printed circuit boards with top and bottom metallization, to which the MEMS component 2 and the ASIC component 3 are fixed as SMD components. The bottom metallization of the MEMS substrate 7 can be assigned to a side of the MEMS substrate 7 facing away from the MEMS component 2, which forms a carrier structure side 4a on which an electrical contacting structure 11 is arranged. As shown in Fig. 1, the MEMS substrate 7 has conductor tracks 17 that extend orthogonally to the first surface 6a and can establish an electrical connection between a bond pad 22 on the first surface 6a and the electrical contacting structure 11. The device 1 can be contacted via an outer side via the electrical contacting structure 11, for example, by being connected to a circuit board of a higher-level system.

[0066] Fig. 1 shows that the MEMS component 2 and the ASIC substrate 8 are each connected to the MEMS substrate 7 via an adhesive bond 13, thus achieving advantageous stress decoupling between the components 2, 3 and the substrates 7, 8. Furthermore, the adhesive bond 13 ensures an airtight seal, which can be used, for example, to optimize the acoustic properties of a device 1 designed as a sound transducer. On one side of the MEMS component 2, which is opposite the side facing the access opening 5, the MEMS component 2 is designed to be exposed in order to be able to provide an additional active surface of the MEMS component 2 at this position, to enable improved interaction of the environment with the MEMS component 2, or, for example, to enable pressure equalization with the environment.For example, a front and a rear volume of an acoustic MEMS component 2 can be formed on the exposed side of the MEMS component 2 and at the access opening 5.

[0067] As can be seen from Fig. 1, wire bridge contacts 12 are arranged on the MEMS component 2 and on the ASIC component 3, which allow the creation of an electrical connection between the components 2, 3. In this case, the components 2, 3 do not have to be directly connected to one another via a common wire bridge contact 12, but the MEMS component 2 can, as shown, be connected via a first wire bridge contact 12 to an electrical connection structure such as a bond pad 22 of the MEMS substrate 7, and the ASIC component 3 can be connected via a further wire bridge contact 12 to the ASIC substrate 8, which in turn is electrically connected to the MEMS substrate 7, for example via an edge metallization 18 shown in more detail in Figs. 4a and 4b.

[0068] In Fig. 1, it is further evident that, according to the illustrated embodiment, a width bA of the ASIC component 3 essentially corresponds to a height hM of the MEMS component 2. This allows a compact device 1 to be created even with an orthogonal alignment of the components 2, 3 to one another.

[0069] Fig. 2 schematically shows a microelectromechanical device 1 according to a second embodiment. This differs from the first embodiment with regard to the mechanical and electrical connection of the MEMS component 2 to the MEMS substrate 7 and of the ASIC component 3 to the ASIC substrate 8. As schematically indicated in Fig. 2, the MEMS component 2 is connected to the MEMS substrate 7 by means of a solder connection 14, and the ASIC component 3 is connected to the ASIC substrate 8 by means of another solder connection 14. The solder connection 14 can be produced by placing solder balls at the intended connection point of the components 2, 3 and placing the components 2, 3 on the substrates 7, 8 using flip-chip technology, wherein the joining partners are subsequently heated and cooled again so that the solder balls can melt and solidify again.The solder connection 14 is electrically conductive and can therefore be used as an electrical connection between the components 2, 3 and the substrates 7, 8, so that an additional wire bridge contact 12 is not required. The solder connections 14 enable advantageous self-centering of the components 2, 3 on the substrates 7, 8 and, moreover, require less lateral space than adhesive connections 13. Fig. 3 schematically shows a microelectromechanical device 1 according to a third embodiment. This differs from the first embodiment in that the carrier structure 4, here in the region of the MEMS substrate 7, has a recess 15 into which the ASIC component 3, together with the ASIC substrate 8, is partially immersed. This achieves improved mechanical protection and a lower overall height of the device 1.The recess 15 is filled with adhesive of an adhesive bond 13 between the MEMS substrate 7 and the ASIC substrate 8 in order to ensure high mechanical stability of the ASIC elements in the recess 15. Alternatively, it would be conceivable, for example, to mechanically stiffen the entire ASIC structure with the ASIC substrate 8 and the ASIC component 3 by means of a polymer potting. The recess 15 can, for example, have been milled into the MEMS substrate 7 before the components 2, 3 are applied. As can be seen from Fig. 3, it is advantageous in the third embodiment if the MEMS substrate 7 is designed as a multilayer printed circuit board. This makes it possible, for example, to provide a central conductor track level with conductor tracks 17, as shown, to which the ASIC substrate 8 with the ASIC component 3, which is embedded in the recess 15, can be electrically connected.

[0070] 4a and 4b schematically show detailed views of a microelectromechanical device 1 according to a fourth embodiment. In FIGS. 4a and 4b, it can be seen that the ASIC substrate 8 has an edge metallization 18 (“edge plating”) in order to be able to establish electrical contact between the ASIC substrate 8 at its end face and a conductor track structure of the MEMS substrate 7. For electrically connecting the edge metallization 18 to a connection structure such as a top metallization of the MEMS substrate 7, the ASIC substrate 8 is bonded to the MEMS substrate 7 in the region of the edge metallization 18 via a solder joint 14. According to the embodiment shown, the ASIC substrate 8 is additionally stabilized by an adhesive joint 13 on the MEMS substrate 7.

[0071] Fig. 5 schematically shows a detailed view of a microelectromechanical device 1 according to a fifth embodiment. This represents a modification of the embodiment shown in Figs. 4a and 4b, in which the ASIC substrate 8 is partially embedded in a recess 15 of the MEMS substrate 7. Via a solder connection 14 and an edge metallization 18, the ASIC substrate 8 is electrically connected to the MEMS substrate 7 via one of its end faces. For additional stabilization of the ASIC substrate 8 in the recess 15, the recess is filled with an underfill 19.

[0072] Fig. 6 schematically shows a microelectromechanical device 1 according to a sixth embodiment. The device 1 according to the sixth embodiment has a carrier structure 4, which is designed as a micro-D circuit carrier 9. This makes it possible to create a compact device 1 with a high level of mechanical protection for the MEMS and ASIC components 2, 3 attached to the carrier structure 4, wherein the micro-D circuit carrier 9 has a high degree of design and shape freedom with regard to its mechanical and electrical structures and their arrangement relative to one another. This allows the device 1 to be individually adapted to predetermined product or process requirements.

[0073] The MID circuit carrier 9 has two opposing access openings 5, between which the MEMS component 2 is embedded in a recess 15 of the MID circuit carrier 9 and fastened to a first surface 6a of the MID circuit carrier 9 by an adhesive connection 13. For example, a front and rear volume of an acoustic MEMS component 2 can be formed through the access openings 5. The ASIC component 3 is embedded in a further recess 15 and fastened to a second surface 6b of the MID circuit carrier 9, which extends substantially orthogonally to the first surface 6a. The ASIC component 3 is fastened to the second surface 6b by a solder connection 14 and is electrically connected to a connection structure (not shown in detail) of the MID circuit carrier 9.An additional underfill 19 supports, secures, and seals the connection of the ASIC component 3 to the second surface 6b. The MEMS component 2 is electrically connected to a connection structure (not shown in detail) of the MID circuit carrier 9 by a wire bridge contact 12. The MID circuit carrier 9 can have, as connection structures, conductive tracks produced, for example, during the manufacture of the MID circuit carrier 9, according to a predetermined three-dimensional track path. Accordingly, according to the embodiment shown, the MEMS component 2 and the ASIC component 3 are indirectly electrically connected to one another via the carrier structure 4. The MID circuit carrier 9 can be connected, for example, to a circuit board of a higher-level system via an electrical contacting structure 11 on a carrier structure side 4a facing away from the components 2, 3.

[0074] In Fig. 6, it is further evident that, according to the illustrated embodiment, a width bA of the ASIC component 3 essentially corresponds to a height hM of the MEMS component 2. This allows a compact device 1 to be created even with an orthogonal alignment of the components 2, 3 to one another.

[0075] Fig. 7 schematically shows a microelectromechanical device 1 according to a seventh embodiment. This differs from the sixth embodiment with regard to the connection of the MEMS component 2 to the first surface 6a of the MID circuit carrier 9. Accordingly, an adhesive connection 13 is supplemented by a solder connection 14 between the MEMS component 2 and the carrier structure 4, so that high mechanical stability and sealing are combined with electrical conductivity at the connection point via the solder connection 14. This makes it possible, for example, to dispense with the wire bridge contact 12 used in the sixth embodiment.

[0076] Fig. 8 schematically shows a microelectromechanical device 1 according to an eighth embodiment. This differs from the sixth embodiment with regard to the connection of the ASIC component 3 to the M1 D circuit carrier 9. Instead of a solder connection 14 and an underfill 19, a material connection is provided here only by an underfill 19, and an electrical connection is implemented via a wire bridge contact 12 between the ASIC component 3 and a connection structure (not shown in detail) of the M1 D circuit carrier 9. Fig. 9 schematically shows a microelectromechanical device 1 according to a ninth embodiment. The ninth embodiment corresponds to a combination of the seventh and eighth embodiments.Here, the MEMS component 2 is connected to the MID circuit carrier 9 via an adhesive connection 13 and a solder connection 14, and the ASIC component 3 is integrally connected to the second surface 6b of the MID circuit carrier 9 via an underfill 19 and is electrically contacted by a wire bridge contact 12.

[0077] Fig. 10 schematically shows a microelectromechanical device 1 according to a tenth embodiment. The tenth embodiment differs from the sixth embodiment in that the electrical contacting structure 11 is not arranged on a support structure side 4a forming an underside of the support structure 4, but rather on a support structure side 4a forming an upper side of the support structure 4. A underside of the support structure 4 can, for example, be closer to the first surface 6a, to which the MEMS component 2 is attached, than a top side of the support structure 4. The arrangement of the electrical contacting structure 11 can, for example, be selected differently depending on an application purpose or an intended installation situation of the device 1.

[0078] Fig. 11 schematically shows a microelectromechanical device 1 according to an eleventh embodiment. The tenth embodiment differs from the sixth embodiment in that the device 1 has a protective membrane 16 for protecting the device 1 from particles and / or moisture. The protective membrane 16 can, as shown in Fig. 11, be arranged, for example, on an upper side of the support structure 4 and advantageously arranged in a depression 20 of the support structure 4. As a result, the protective membrane 16 is mechanically protected and can be easily attached to the support structure 4.

[0079] Fig. 12 shows schematically a microelectromechanical device

[0080] 1 according to a twelfth embodiment. The device 1 according to the sixth embodiment has a carrier structure 4, which is designed as an additively manufactured layered circuit carrier 10. This allows a carrier structure 4, individually adapted to the MEMS and ASIC components 2, 3, with the desired mechanical and electrical structures, to be created directly in the layered structure. A protective membrane 16 can also be integrated into the layered structure, which can be mechanically stabilized, for example, by support structures 21. As can be seen from Fig. 12, the MEMS component 2, apart from two opposing access openings 5, is embedded or encapsulated in the layered structure of the layered circuit carrier 10 and thus reliably sealed, so that, for example, acoustic leakage paths between the front and rear volumes formed by the access openings 5 ​​are avoided.The layered structure forms a housing structure for protecting the device 1 from mechanical impacts and undesirable environmental influences such as particle and liquid ingress. According to the twelfth embodiment, the MEMS component 2 is attached to a first surface 6a of the carrier structure 4, which can, for example, be a layer surface of a layer produced in the layered structure, and is also framed by further layers of the layered structure. The ASIC component 3 is attached to a second surface 6b of the carrier structure 4, which is formed by lateral layer boundaries of the layered structure, and is also framed by further layers of the layered structure. For external contacting of the device 1, an electrical contacting structure 11 is provided on an outer carrier structure side 4a of the carrier structure 4.

[0081] Fig. 13 schematically shows a simplified flow diagram of a method 100 for producing a microelectromechanical device 1. According to Fig. 13, the method 100 comprises the following steps:

[0082] - Providing a MEMS component 2 and an ASIC component 3 in a first step 110;

[0083] - Providing or producing a support structure 4 with an access opening 5 in a second step 120;

[0084] - Attaching the MEMS component 2 to a first surface 6a of the support structure 4 such that the MEMS component 2 spans the access opening 5 in a third step 130; and - Attaching the ASIC component 3 to a second surface 6b of the support structure 4 in a fourth step 140, wherein the second surface 6b is oriented substantially orthogonally to the first surface 6a of the support structure 4.

[0085] As explained in the first to twelfth embodiments, a MEMS substrate 7 and an ASIC substrate 8 can be provided and connected to one another as the carrier structure 4, wherein the ASIC substrate 8 is arranged substantially orthogonally to the MEMS substrate 7. Alternatively, it is possible to provide the carrier structure 4 as a MID circuit carrier 9 or to produce it as a layered circuit carrier 10 using an additive manufacturing process.

[0086] With the presented microelectromechanical device 1 according to the above-described embodiments and by means of the described method 100 for producing the device 1, it is possible to provide a compact, space-optimized, robust and easy-to-manufacture microelectromechanical device 1.

Claims

Claims 1. A microelectromechanical device (1) comprising a MEMS component (2) and an ASIC component (3) which are attached to a support structure (4) of the device (1), wherein the support structure (4) has an access opening (5) adjacent to the MEMS component (2), and wherein the MEMS component (2) is attached to a first surface (6a) of the support structure (4) and the ASIC component (3) is attached to a second surface (6b) of the support structure (4), wherein the second surface (6b) is oriented substantially orthogonal to the first surface (6a) of the support structure (4).

2. Device (1) according to claim 1, wherein the support structure (4) comprises a MEMS substrate (7) to which the MEMS component (2) is attached, and wherein the support structure (4) comprises an ASIC substrate (8) arranged substantially orthogonally to the MEMS substrate (7), to which the ASIC component (3) is attached.

3. Device (1) according to claim 1, wherein the carrier structure (4) is an M ID circuit carrier (9).

4. Device (1) according to claim 1, wherein the carrier structure (4) is an additively manufactured layered circuit carrier (10).

5. Device (1) according to one of the preceding claims, wherein the carrier structure (4) has an electrical contacting structure (11) on a carrier structure side (4a) facing away from the MEMS component (2) and the ASIC component (3).

6. Device (1) according to one of the preceding claims, wherein the MEMS component (2) and the ASIC component (3) are electrically connected to one another by at least one wire bridge contact (12).

7. Device (1) according to one of the preceding claims, wherein the MEMS component (2) and / or the ASIC component (3) is connected to the carrier structure (4) by means of an adhesive connection (13).

8. Device (1) according to one of the preceding claims, wherein the MEMS component (2) and / or the ASIC component (3) is connected to the carrier structure (4) by means of a solder connection (14).

9. Device (1) according to one of the preceding claims, wherein the carrier structure (4) has at least one recess (15) into which the MEMS component (2) and / or the ASIC component (3) is immersed at least in sections.

10. Device (1) according to one of the preceding claims, wherein the ASIC component (3) has a width (bA) which substantially corresponds to a height (IIM) of the MEMS component (2).

11. Device (1) according to one of the preceding claims, wherein a protective membrane (16) is arranged on the support structure (4).

12. Device (1) according to one of the preceding claims, wherein the device (1) is designed as a sound transducer.

13. A method (100) for producing a microelectromechanical device (1), comprising the steps: - Providing a MEMS component (2) and an ASIC component (3) (110); - providing or producing a support structure (4) with an access opening (5) (120); - attaching the MEMS component (2) to a first surface (6a) of the support structure (4) such that the MEMS component (2) spans (130) the access opening (5); and - Attaching the ASIC component (3) to a second surface (6b) of the carrier structure (4) (140), wherein the second Surface (6b) is aligned substantially orthogonal to the first surface (6a) of the support structure (4).

14. The method according to claim 13, wherein a MEMS substrate (7) and an ASIC substrate (3) are provided as the carrier structure (4) and are connected to one another, wherein the ASIC substrate (3) is arranged substantially orthogonally to the MEMS substrate (7).

15. The method according to claim 13, wherein a MID circuit carrier (9) is provided as the carrier structure (4).

16. The method according to claim 13, wherein the carrier structure (4) is produced as a layered circuit carrier (10) by means of an additive manufacturing process.

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