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

Abstract

The present invention relates to a microelectromechanical device (1) having a MEMS device (2) and an ASIC device (3) fixed on a support structure (4) of the device (1), wherein the support structure (4) has an inlet (5) adjacent to the MEMS device (2), and the MEMS device (2) is fixed on a first surface (6a) of the support structure (4), and the ASIC device (3) is fixed on a second surface (6b) of the support structure (4), wherein the second surface (6b) is oriented substantially orthogonally to the first surface (6a) of the support structure (4). The present invention also relates to a method (100) for manufacturing such a microelectromechanical device (1).

Description

Technical Field

[0001] This invention relates to a microelectromechanical device (MEMS) and a method for manufacturing a MEMS. Background Technology

[0002] Microelectromechanical devices, also known as MEMS devices, and methods for manufacturing microelectromechanical devices are known from the prior art.

[0003] US 9,407,997 B2 describes a MEMS device having a substrate element and a cover element, with a MEMS microphone device arranged between them, and an integrated circuit in the substrate element. The acoustic aperture of the MEMS device extends through the substrate element and the integrated circuit.

[0004] US 2015 / 0195659 A1 relates to a MEMS microphone having a substrate element, a cover element, and an interposer layer that surrounds a cavity having a MEMS structure and an ASIC. An electrical connection is established between the substrate element and the cover element through the interposer layer.

[0005] CN 2 11 429 522 U discloses a MEMS microphone having a housing in which a first circuit board and a second circuit board oriented perpendicular to the first circuit board are arranged, the second circuit board being selectively connected to a MEMS chip or an ASIC chip.

[0006] CN 2 10 927 973 U discloses an acoustic MEMS sensor having a first substrate and a second substrate, wherein a MEMS chip is disposed on the first substrate, and an ASIC chip electrically connected to the MEMS chip is integrated in the first substrate. Summary of the Invention

[0007] According to the features of independent claim 1, a microelectromechanical device is proposed, having a MEMS device and an ASIC device fixed on a carrier structure of the device, wherein the carrier structure has an inlet adjacent to the MEMS device, and the MEMS device is fixed on a first surface of the carrier structure, and the ASIC device is fixed on a second surface of the carrier structure, wherein the second surface is oriented substantially orthogonally to the first surface of the carrier structure.

[0008] This provides a compact microelectromechanical device in which the available structural space, limited by the access port, is better utilized through the orthogonal orientation of MEMS and ASIC devices. The reduced space required for the devices increases the degree of configurational freedom in device fabrication, as the devices can be arranged with freely selectable spacing between them. In particular, the ASIC devices can be arranged spaced apart from the access port. Furthermore, the devices can be clearly separated and demarcated from each other, thereby reducing or eliminating mutual mechanical or electrical influences. The proposed arrangement avoids the stacking of MEMS and ASIC devices.

[0009] Microelectromechanical devices (MEMS) can be devices with microstructures and electromechanical transducers, the transducers being configured, for example, to interact with the device's surrounding environment. Microstructures can be fabricated, in particular, using semiconductor technology and can, for example, have mechanical, optical, physical, and / or chemical components and / or functions. Such devices can also be used as miniature sensors or actuators. For example, microstructures can be configured to detect or generate fluid flow or fluid pressure. In particular, microstructures can be adapted to detect or generate sound pressure to constitute acoustic MEMS.

[0010] MEMS devices can be components of microelectromechanical devices (MEMS) having at least one movable microstructure for interacting with the device's surrounding environment. This movable microstructure, such as an elastically deflectable diaphragm, can define a MEMS functional plane of the MEMS device. The MEMS functional plane can extend parallel to a first surface on which the MEMS device is disposed, and the MEMS device can have one or more MEMS functional planes, which can be formed, for example, by one or more elastic diaphragms.

[0011] An ASIC device can be a component of a microelectromechanical system (MEMS) that constitutes a signal processing unit for applying and processing signals from the MEMS device, such as signals for controlling or analyzing MEMS devices. The abbreviation ASIC stands for Application-Specific Integrated Circuit, which is an electronic circuit implemented as an integrated loop. Therefore, an ASIC device has at least one circuit structure that defines an ASIC functional plane. The ASIC functional plane may extend parallel to a second surface of the carrier structure on which the ASIC device is disposed. An ASIC device may have one or more ASIC functional planes, which may be formed, for example, by circuit planes.

[0012] By arranging MEMS and ASIC devices on mutually perpendicularly oriented surfaces of the support structure, the aforementioned functional planes of the devices can also be oriented substantially perpendicularly to each other, such that, for example, the circuit structure of the ASIC device extends along a spatial axis different from that of the movable microstructure of the MEMS device. This allows for a more compact implementation of the device while achieving better separation of the functional planes. In particular, it allows the microstructure of the MEMS device to interact with the surrounding environment without interference through the entry points of the support structure.

[0013] The support structure can be an electromechanical component of a device that includes spatial support and fixing devices for MEMS and ASIC devices, as well as electrical connection and contact structures to enable electrical contact between the devices and the device as a whole from external sources. The support structure has a first surface on which the MEMS devices are disposed, and a second surface on which the ASIC devices are disposed, wherein the first and second surfaces are substantially orthogonally oriented to each other. Here, orthogonal orientation is understood as the first and second surfaces intersecting each other at a perpendicular angle along or extending along a spatial axis or spatial plane. Therefore, the first and second surfaces do not necessarily need to be directly adjacent to each other, but can be imaginarily extended in the direction of their plane extension to determine their orientation relative to each other. Thus, for example, a lateral offset can be provided between the MEMS devices and the ASIC devices. In principle, within the limits of technical conditions, such as the required lateral spacing and wire bridging sections, the lateral offset between the MEMS devices and the ASIC devices can be freely chosen. The term "lateral" can refer to a spatial direction parallel to the plane extension of the first or second surface, respectively. Fixing a device to a surface specifically implies permanent fixation, which means, for example, cannot be disassembled without damage and can be achieved through bonding methods based on material locking or additive manufacturing methods.

[0014] The support structure has an inlet that allows the MEMS device, particularly its movable microstructures, to interact with the surrounding environment. The MEMS device may have an active surface in the region of the inlet, configured to detect or influence environmental conditions. The inlet may extend through a first surface, allowing the MEMS device to be anchored on the first surface in a region adjacent to the inlet. Thus, the MEMS device can bridge across the inlet. Depending on the implementation, the inlet may, for example, form a pressure inlet or an acoustic aperture for sound entry or exit. According to an advantageous configuration, the MEMS device is also configured to be exposed on the side opposite the inlet to, for example, achieve better interaction between the MEMS device and its surrounding environment or to achieve pressure balance between the device and its surrounding environment. For example, an exposed configuration can be achieved if the support structure forms a predominantly planar support structure on which the MEMS device is disposed. For example, the MEMS substrate and / or ASIC substrate can form a planar support structure because such a substrate can have an extension of the predominantly planar surface. If the support structure is constructed to surround the MEMS device on multiple sides, the support structure may, for example, have two opposing entrances between which the MEMS device is arranged. For example, in acoustic microelectromechanical devices, the entrances may form a front cavity volume and a rear cavity volume.

[0015] According to one embodiment, the carrier structure may have a MEMS substrate on which MEMS devices are fixed, and the carrier structure may have an ASIC substrate arranged substantially orthogonally to the MEMS substrate on which ASIC devices are fixed. This provides a simple and cost-effective carrier structure that provides suitable first and second surfaces for fixing the MEMS and ASIC devices via the MEMS and ASIC substrates. Furthermore, such a carrier structure enables a space-saving, compact device structure. The ASIC substrate may be orthogonally fixed to the MEMS substrate, for example, by locking onto a surface material of the MEMS substrate at an end of the ASIC substrate, the surface forming a first surface of the MEMS substrate or extending parallel to the first surface. The MEMS and / or ASIC substrates may be configured as circuit boards, for example, as a two-layer circuit board with top and bottom metallization, wherein, depending on the embodiment, a multilayer circuit board with more than two layers may also be advantageous. The MEMS and ASIC devices may be arranged as surface mount devices (SMDs) on the circuit board. The MEMS and / or ASIC substrates may have printed conductors extending parallel to and / or orthogonally to the substrate surfaces of their respective substrates. Furthermore, it is conceivable that MEMS substrates and / or ASIC substrates are provided with edge plating to enable contact on the end faces of the substrate.

[0016] According to an alternative implementation, the carrier structure can be a MID (Molded Interconnect Device). The abbreviation MID stands for Molded Interconnect Device, referring to an injection-molded three-dimensional circuit carrier. The basic geometry of the MID is manufactured by plastic injection molding, and then conductive structures are set using special methods, such as laser structuring or laser activation, followed by metallization. For example, a three-dimensional plastic component with integrated printed conductors, wire bonding, or solder pads can be provided, enabling electrical connections between devices arranged on the circuit carrier and external contacts of the circuit carrier. Using the carrier structure formed by the MID circuit carrier, a compact microelectromechanical device can be provided that provides strong mechanical protection for devices fixed to the carrier structure. The MID circuit carrier relates to a high degree of configurational and shape freedom in the mechanical and electrical structures arranged on the carrier structure and their relative arrangement. For example, the routing of three-dimensional printed conductors can be implemented in a simple manner, or spatial recesses, slots, cavities, and receptacles for devices and other components of the device, such as protective films, can be implemented on the MID circuit carrier. Therefore, the form of the device can be individually adapted to the given product requirements or process requirements for further processing.

[0017] According to an alternative implementation, the carrier structure can be an additively manufactured layered circuit carrier. Such a carrier structure can be a layered fabricated carrier structure generated during the fabrication of the microelectromechanical device (MEMS). Thus, the carrier structure can be individually adapted to the device and predefined mechanical and electrical requirements of the device. The carrier structure can have additively manufactured mechanical structures and optionally additively manufactured electrical structures. For example, the carrier structure can have a complex three-dimensional printed wiring structure generated layer by layer. Furthermore, for example, a protective diaphragm can be integrated into the layered structure. MEMS devices can be embedded in the layered circuit carrier, thereby reliably sealing them through the resulting layers. For example, for acoustic MEMS devices, this can achieve improved acoustic characteristics, such as avoiding acoustic leakage paths.

[0018] According to one embodiment, the carrier structure may have an electrical contact structure on the carrier structure side facing away from the MEMS device and ASIC device. This carrier structure side may particularly form the outer side of the carrier structure, such as the lower side, where an inlet may be arranged, or an upper side opposite the lower side of the carrier structure. This allows external access to the microelectromechanical device (MEMS), for example, connection to a circuit board or electrical equipment. The electrical contact structure can, for example, control the MEMS or detect signals, such as measurement signals of the MEMS. The electrical contact structure can be connected to the MEMS device and / or ASIC device via electrical wire paths passing through the carrier structure. For example, printed wires may extend between the top and bottom metallizations in a MEMS substrate configured as a circuit board. For example, printed wires may pass through the carrier structure configured as a MID circuit carrier in a three-dimensional circuit path. This establishes an electrical connection between the device and the electrical contact structure.

[0019] According to one embodiment, MEMS devices and ASIC devices can be electrically connected to each other via at least one lead bridge contact. Such lead bridge contacts can be manufactured in a simple and cost-effective manner using wire bonding methods, establishing a reliable electrical connection between the MEMS device and the ASIC device. Furthermore, it is conceivable to establish electrical connections between the MEMS device and / or ASIC device and the connection structure of the carrier structure via the lead bridge contacts, such as solder pads or bonding pads on the MEMS substrate, or connection structures of the MID circuit carrier, wherein the aforementioned connection structures can in turn be electrically connected to the electrical contact structures of the carrier structure. According to the embodiment, MEMS devices and ASIC devices can be directly electrically connected to each other via lead bridge contacts, or indirectly electrically connected to each other via the carrier structure, for example, through lead bridge contacts between the MEMS device or ASIC device and the carrier structure configured as a MID circuit carrier, thereby achieving indirect contact between the corresponding other device through the lead bridge contacts and the carrier structure.

[0020] According to one embodiment, MEMS devices and / or ASIC devices can be connected to a carrier structure via adhesive bonding. Adhesive bonding enables advantageous stress decoupling between the MEMS and / or ASIC devices and the carrier structure. Furthermore, adhesive bonding allows for a sealed, particularly hermetically tight, seal between the device and the carrier structure, which, for example, improves the acoustic characteristics of the microelectromechanical device (MEMS) in acoustic MEMS devices, such as speakers or microphones. Additionally, if MEMS devices and / or ASIC devices are connected to the carrier structure via adhesive bonding, the microelectromechanical device is easier to manufacture. Liquid adhesives can be used as the adhesive, which may be, for example, epoxy or silicon materials. Depending on the embodiment and the connection location of the device, conductive or non-conductive adhesives can be used. In principle, adhesive bonding can exist, for example, between a MEMS device and a MEMS substrate, between an ASIC device and an ASIC substrate, between a MEMS substrate and an ASIC substrate, between a MEMS device and a MID circuit carrier, and between an ASIC device and a MID circuit carrier.

[0021] According to one embodiment, MEMS devices and / or ASIC devices can be connected to a carrier structure via soldering. To create a soldering connection, a specialized solder library, also known as solder balls, can be placed at the connection site, for example, before the mating components are arranged on each other. For example, the device can first have the solder library set and applied to a pre-defined surface using a flip-chip process. Electronic solder, such as silver-copper-tin solder, can be used as the soldering material. This soldering connection is conductive and can therefore be used as an electrical connection between the mating components, eliminating the need for additional lead bridge contacts. Thus, through soldering, the device is mechanically and electrically connected to the substrate. Furthermore, the surface stress of the solder balls can be advantageously utilized during device fabrication, as they act as a self-centering agent between the structures to be connected. Moreover, compared to adhesive bonding, soldering requires less lateral space on the bonding surface, allowing for smaller manufacturing tolerances and shorter spacing, or so-called gaps, between device structures. According to an extension of the embodiment, the soldering connection can be sealed and mechanically stabilized using an adhesive or underfill, also known as an adhesive or underfill. In principle, brazing connections can exist, for example, between MEMS devices and MEMS substrates, between ASIC devices and ASIC substrates, between MEMS substrates and ASIC substrates, between MEMS devices and MID circuit carriers, and between ASIC devices and MID circuit carriers. Furthermore, it is conceivable that the microelectromechanical device has an adhesive connection at at least one of the aforementioned connection locations and a brazing connection at at least another of the aforementioned connection locations, thereby allowing the advantages of each connection method to be utilized for different connection locations and adaptable to the connection locations.

[0022] According to one embodiment, the carrier structure may have at least one recess into which MEMS devices and / or ASIC devices extend at least segmentally. This recess can thus form a receiving portion for the MEMS devices and / or ASIC devices, thereby achieving improved mechanical protection and simplified connection of the devices to the carrier structure via a plug-in connection. Furthermore, this can reduce the system height of the ASIC system including the ASIC substrate and ASIC devices. The recess can be introduced, for example, into the MEMS substrate of the carrier structure, such as by milling, wherein the MEMS substrate can be configured as a multilayer circuit board to provide a recess with electrically contactable surfaces, and can also have a predefined minimum thickness to ensure sufficient mechanical stability, for example, against twisting and warping. The recess can be formed on the MID circuit carrier as a geometric notch, for example, by suitable injection molding. For example, for additively manufactured layered circuit carriers, the recess can be introduced into the layer structure of the layered circuit carrier as a layer notch or temporary layer structuring. According to an extension of the embodiment, the recess can be at least partially filled, for example, with adhesive or underfill after accommodating the device, to achieve even greater mechanical stability of the device. For example, an ASIC substrate with connected ASIC devices can extend at least segmentally into a recess in a MEMS substrate and be secured in the recess by an underfill or adhesive. Alternatively, the ASIC substrate and ASIC devices can be mechanically reinforced, for example, by a polymer casting compound. Furthermore, it is conceivable that the support structure has additional recesses for other mechanical or electrical structures different from the MEMS or ASIC devices.

[0023] According to one embodiment, the ASIC device can have a width that substantially corresponds to the height of the MEMS device. This provides a flat, compact microelectromechanical device (MEMS) even when the devices are arranged substantially orthogonally to each other. According to this embodiment, by orienting the devices relative to each other at right angles, these devices can have comparable heights when viewed from the same spatial axis. This allows for a reliable and simple electrical connection between the ASIC device and the MEMS device, for example, via lead bridge contacts between the devices. Furthermore, the carrier structure and, if necessary, the additional MEMS housing can be designed as a compact structure, advantageously maximizing the use of mounting space. The height of the MEMS device can be an extension of the MEMS device perpendicular to a first surface on which it is fixed. The width of the ASIC device can be an extension of the ASIC device parallel to a second surface on which it is fixed.

[0024] According to one embodiment, a protective diaphragm can be arranged on the supporting structure. The protective diaphragm may be, for example, a diaphragm for protecting the device from particles or moisture, and is arranged, for example, on the upper and / or lower side of the supporting structure. According to an extension, the protective diaphragm may be arranged in a recessed portion of the supporting structure. Thus, the protective diaphragm can be arranged in a mechanically protected manner, and furthermore, it can be secured more simply and securely.

[0025] According to one embodiment, the device can be configured as an acoustic transducer. Using the proposed microelectromechanical device, a compact, robust, and high-performance acoustic transducer can be provided. The acoustic transducer can, for example, be a microphone or a loudspeaker. For the acoustic transducer, the MEMS device can be configured as an acoustic MEMS device and, for example, have at least one deflectable diaphragm as a microstructure for detecting or generating sound pressure. In the acoustic transducer, the inlet can, for example, be formed as an acoustic aperture to construct the front or rear cavity volume of the acoustic MEMS device.

[0026] However, in principle, this device can also be configured as a non-acoustic sensor or actuator. For example, it can be configured as an environmental sensor, such as a pressure sensor or a humidity sensor, or as a micro-valve or micro-pump for microfluidic applications.

[0027] According to the selected embodiment, the microelectromechanical device (MEMS) may have a housing structure for protecting the device from mechanical forces and undesirable environmental influences, such as particle ingress and liquid ingress. The housing structure may, for example, be a cover structure that encloses the MEMS device and the ASIC device, or an additively generated layer structure that houses the device, for example, enabling substantially complete encapsulation of the ASIC device.

[0028] The present invention also relates to a method for manufacturing a microelectromechanical device, comprising the following steps: We provide MEMS devices and ASIC devices; Provide or produce load-bearing structures with inlets; The MEMS device is fixed to the first surface of the support structure, such that the MEMS device spans the inlet; and The ASIC device is fixed on the second surface of the support structure, wherein the second surface is oriented substantially orthogonal to the first surface of the support structure.

[0029] Using the proposed method, compact microelectromechanical devices (MEMS) can be fabricated in a simple manner, where the available structural space, which is limited by the access port, is better utilized through the orthogonal orientation of MEMS and ASIC devices. This method offers high configurational freedom due to the reduced space required for the devices, as they can be arranged relative to each other with freely selectable spacing. In particular, ASIC devices can be arranged spaced apart from the access port. Furthermore, these devices can be clearly separated and demarcated from each other, thereby reducing or eliminating mutual mechanical or electrical influences during device operation.

[0030] According to one embodiment, a MEMS substrate and an ASIC substrate can be provided as a carrier structure and interconnected, wherein the ASIC substrate is arranged substantially orthogonally to the MEMS substrate. This allows for the use of a simple and inexpensive carrier structure that provides suitable first and second surfaces for fixing the MEMS and ASIC devices via the MEMS and ASIC substrates. The ASIC substrate can be orthogonally oriented onto the MEMS substrate, for example, by locking onto a surface material of the MEMS substrate at an end of the ASIC substrate, the surface forming a first surface of the MEMS substrate or extending parallel to the first surface. In this method, for example, a chip-on-a-board (COP) process can be employed, where the MEMS and ASIC devices are respectively fixed onto the MEMS and ASIC substrates as SMD components via direct mounting. Here, for example, the MEMS device can be bonded to the MEMS substrate, and the ASIC device can be bonded to the ASIC substrate; the MEMS and ASIC substrates with the bonded devices are positioned and interconnected, and then the MEMS and ASIC devices are electrically connected to each other via lead bridge contacts. Furthermore, electrical contact structures can be provided or formed on the carrier structure side away from the MEMS and ASIC devices, for example, on the underside of the MEMS substrate. In addition, recesses can be introduced into the MEMS substrate, for example, by milling, and the ASIC device is embedded in the recess at least in sections.

[0031] Instead of adhesive bonding between devices and substrates, they can be secured to each other by soldering. Here, for example, a flip-chip process can be used, in which a solder library is applied to the contact pads of the device, and the device is rotated about its axis and placed on the corresponding substrate. The prepared unit consisting of the device and substrate is heated, causing the solder in the solder library to melt and subsequently resolidify. Through soldering, the device is mechanically and electrically connected to the substrate. Optionally, the soldered connection can be supplemented with sealing and mechanical stabilization using adhesives or underfill.

[0032] According to an alternative embodiment, a MID circuit carrier can be provided as a carrier structure. Utilizing the carrier structure formed by the MID circuit carrier, a compact microelectromechanical device (MEMS) can be provided, offering high mechanical protection for devices fixed to the carrier structure. The MID circuit carrier has high configurational and shape freedom in terms of the mechanical and electrical structures disposed on the carrier structure and their relative arrangement. Depending on the embodiment, MEMS devices and / or ASIC devices can be fixed to the MID circuit carrier, for example, by adhesive and / or solder connections, and optionally by lead bridge contacts. Advantageously, the MID circuit carrier can have recesses for the MEMS devices and / or ASIC devices respectively, with the corresponding devices embedded in the recesses and, for example, fixed to the bottom surface of the recesses. Furthermore, electrical contact structures can be provided or formed on the carrier structure side away from the MEMS devices and ASIC devices, such as the lower or upper side of the MID circuit carrier.

[0033] According to an alternative implementation, a circuit carrier can be produced as a layered structure carrier using additive manufacturing methods. This allows for the integration of device positioning with the fabrication of the device housing structure in terms of process technology. Therefore, the carrier structure can be produced in layers, and MEMS devices and ASIC devices can be integrated into the layers. For example, devices can be placed on already produced layers and then at least partially wrapped or covered by other layers. Through additive manufacturing, the carrier structure can be individually adapted to the device and predefined mechanical and electrical requirements of the device. Furthermore, such carrier structures can provide simple and flexible prototypes of microelectromechanical devices, for example, for experimental and demonstration purposes. By selecting a suitable additive manufacturing method, also known as 3D printing, mechanical and electrical structures with high degrees of configurational freedom can be produced during the additive manufacturing process to construct layered circuit carriers. For example, complex three-dimensional printed wires can be produced layer by layer. Therefore, for example, additional lead bridge contacts and correspondingly arranged wire bonding pads on the device can be eliminated, thus also avoiding compliance with associated minimum or maximum spacing requirements. Alternatively, lead bridge contacts can be directly produced using additive manufacturing methods, eliminating the need for subsequent wire bonding. Furthermore, the edge spacing that needs to be considered in the corner and side regions of MEMS devices can be reduced. Additionally, the increased mounting space volume of the carrier structure can be used for laying printed conductors. Furthermore, for example, protective diaphragms can be directly integrated into the layer structure, eliminating the need for subsequent fixing. Moreover, MEMS devices can be embedded in the layer structure circuit carrier and thus reliably sealed, thereby achieving better acoustic characteristics, for example, for acoustic MEMS devices, by avoiding acoustic leakage paths. Furthermore, the subsequent capping process can be eliminated because the device is already encapsulated in the layer structure during manufacturing. Electrical contact structures can be provided or created on the carrier structure side away from the MEMS and ASIC devices, such as on the underside or top side of the layer structure circuit carrier.

[0034] Very generally, in the context of this application, unless otherwise expressly defined, the word “a” should not be understood as a numeral, but rather as an indefinite article having the meaning of “at least one”. Attached Figure Description

[0035] This invention allows for various implementations, which will be described in more detail below with reference to embodiments and the accompanying drawings. The drawings are shown schematically: Figure 1 – A cross-sectional view of the microelectromechanical device according to the first embodiment; Figure 2 – A cross-sectional view of the microelectromechanical device according to the second embodiment; Figure 3 – A cross-sectional view of the microelectromechanical device according to the third embodiment; Figures 4a-4b– Detailed view of the cross-sectional view of the microelectromechanical device according to the fourth embodiment; Figure 5 – Detailed view of the cross-sectional view of the microelectromechanical device according to the fifth embodiment; Figure 6 – A cross-sectional view of the microelectromechanical device according to the sixth embodiment; Figure 7 – A cross-sectional view of a microelectromechanical device according to the seventh embodiment; Figure 8 – A cross-sectional view of the microelectromechanical device according to the eighth embodiment; Figure 9 – A cross-sectional view of a microelectromechanical device according to the ninth embodiment; Figure 10 – A cross-sectional view of a microelectromechanical device according to the tenth embodiment; Figure 11 – A cross-sectional view of the microelectromechanical device according to the eleventh embodiment; Figure 12 – A cross-sectional view of the microelectromechanical device according to the twelfth embodiment; Figure 13 – A simplified flowchart of a method for manufacturing microelectromechanical devices. Detailed Implementation

[0036] Figure 1 A microelectromechanical device 1 according to a first embodiment is shown schematically. The device 1 includes a MEMS device 2 and an ASIC device 3. The MEMS device 2 and the ASIC device 3 are fixed to a support structure 4 of the device 1. The support structure 4 has an inlet 5 adjacent to the MEMS device 2. The MEMS device 2 is fixed to a first surface 6a of the support structure 4. The ASIC device 3 is fixed to a second surface 6b of the support structure 4. The second surface 6b is oriented substantially orthogonally to the first surface 6a. With the described microelectromechanical device 1, a compact device 1 with improved structural space utilization is achieved, despite the reduced usable space due to the presence of the inlet 5.

[0037] like Figure 1As seen, the MEMS device 2 bridges the inlet 5. Through the inlet 5, the microstructures of the MEMS device 2 (not further shown) can interact with the surrounding environment of the device 1, for example, by being deflected by ambient pressure or sound pressure as a movable diaphragm, which can be detected, for example, by electrostatics. Conversely, the movable diaphragm of the MEMS device 2 can be actively deflected by an applied signal to generate, for example, fluid pressure or sound pressure. The device 1 can, for example, form an acoustic microelectromechanical device 1 in the form of an acoustic transducer, such as a microphone or speaker, or form a pressure sensor, and the inlet 5 can, for example, form a pressure inlet or an acoustic aperture for sound entry and / or sound exit. The MEMS device 2 can have one or more active surfaces, which can, for example, be arranged on the side of the MEMS device 2 facing the inlet 5 and on the side of the MEMS device 2 opposite to the aforementioned side. The MEMS device 2 is electrically connected to an ASIC device 3. The ASIC device 3 can, for example, be configured to apply and process signals from the MEMS device 2, for example, to control the microstructures of the MEMS device 2 or to transmit measurement signals detected by the microstructures to the ASIC device 3. The support structure 4 serves as the mechanical foundation for the MEMS device 2 and the ASIC device 3, and, depending on the implementation, can provide electrical connection between the MEMS device 2 and the ASIC device 3 and / or prepare for the external connection of the device 1.

[0038] according to Figure 1 In the illustrated embodiment, the support structure 4 is a MEMS substrate 7, on which the MEMS device 2 is fixed. The ASIC device 3 is fixed to an ASIC substrate 8, which is arranged substantially orthogonally to the MEMS substrate 7. Thus, a flat-structured device 1 is obtained using a simple and low-cost support structure 4. The MEMS substrate 7 has a first surface 6a on which the MEMS device 2 is fixed, and the ASIC substrate 8 has a second surface 6b on which the ASIC device 3 is fixed. The ASIC substrate 8 is material-locked to the first surface 6a of the MEMS substrate 7 at one end, and is thus orthogonally fixed to the MEMS substrate 7. Figure 1 As shown, the MEMS substrate 7 and ASIC substrate 8 can be constructed as a double-layer circuit board with top and bottom metallization, and the MEMS device 2 and ASIC device 3 are fixed on the circuit board as SMD components. The bottom metallization of the MEMS substrate 7 can be assigned to the side of the MEMS substrate 7 opposite to the MEMS device 2, which forms the support structure side 4a, and the electrical contact structure 11 is arranged on the support structure side. Figure 1As illustrated, the MEMS substrate 7 has printed conductors 17 that extend orthogonally to the first surface 6a and can establish an electrical connection between bonding pads 22 on the first surface 6a and electrical contact structures 11. Through the electrical contact structures 11, the device 1 can be contacted from the outside, for example, connected to a circuit board of a higher-level system.

[0039] exist Figure 1 As shown, MEMS device 2 and ASIC substrate 8 are connected to MEMS substrate 7 via adhesive connections 13, thereby achieving advantageous stress decoupling between devices 2 and 3 and substrates 7 and 8. Furthermore, adhesive connections 13 ensure hermetically sealed operation, which can, for example, optimize the acoustic characteristics of device 1 configured as an acoustic transducer. On the side of MEMS device 2 opposite to the side facing inlet 5, MEMS device 2 is configured to be exposed, allowing for the placement of an additional active surface of MEMS device 2 at this location, enabling better interaction with the surrounding environment, or, for example, achieving pressure balance with the surrounding environment. For example, the front and rear cavity volumes of the acoustic MEMS device 2 can be constructed on the exposed side of MEMS device 2 and at inlet 5.

[0040] like Figure 1 As seen, lead bridge contacts 12 are arranged on MEMS device 2 and ASIC device 3, allowing electrical connections to be established between devices 2 and 3. Here, devices 2 and 3 do not necessarily connect directly to each other via a common lead bridge contact 12. Instead, as illustrated, MEMS device 2 can be connected to an electrical connection structure, such as the bonding pad 22 of the MEMS substrate 7, via a first lead bridge contact 12, while ASIC device 3 can be connected to an ASIC substrate 8, for example, via another lead bridge contact 12. Figure 4a and 4b The edge metallization 18, shown in more detail, is electrically connected to the MEMS substrate 7.

[0041] exist Figure 1 It can also be seen that, according to the illustrated embodiment, the width b of the ASIC device 3 A Basically corresponding to the height h of MEMS device 2 M Therefore, even when devices 2 and 3 are orthogonally oriented, a compact device 1 can be achieved.

[0042] Figure 2 A microelectromechanical device 1 according to a second embodiment is shown schematically. This second embodiment differs from the first embodiment in the mechanical and electrical attachment of the MEMS device 2 to the MEMS substrate 7 and the ASIC device 3 to the ASIC substrate 8. For example... Figure 2As schematically shown, MEMS device 2 is connected to MEMS substrate 7 via solder joint 14, and ASIC device 3 is attached to ASIC substrate 8 via another solder joint 14. Here, the solder joint 14 is manufactured by placing solder balls at predetermined connection points of devices 2 and 3 and placing devices 2 and 3 on substrates 7 and 8 using a flip-chip process, wherein the mating components are subsequently heated and then cooled, allowing the solder balls to melt and resolidify. The solder joint 14 is configured to be conductive, and therefore can be used as an electrical connection between devices 2 and 3 and substrates 7 and 8, thus eliminating the need for additional lead bridge contacts 12. The solder joint 14 allows devices 2 and 3 to advantageously self-center on substrates 7 and 8, and further requires less lateral space compared to adhesive joint 13.

[0043] Figure 3 A microelectromechanical device 1 according to a third embodiment is illustrated schematically. This third embodiment differs from the first embodiment in that the support structure 4 has a recess 15 in a region of the MEMS substrate 7, into which the ASIC device 3, along with the ASIC substrate 8, extends in sections. This achieves better mechanical protection and a smaller structural height for the device 1. The recess 15 is filled with an adhesive for the adhesive connection 13 located between the MEMS substrate 7 and the ASIC substrate 8 to ensure high mechanical stability of the ASIC element within the recess 15. Alternatively, for example, it can be envisioned that the entire ASIC structure having the ASIC substrate 8 and the ASIC device 3 is mechanically reinforced by a polymer casting. The recess 15 can, for example, be milled into the MEMS substrate 7 before the devices 2 and 3 are applied. Figure 3 As seen in the third embodiment, it is advantageous that the MEMS substrate 7 is constructed as a multilayer circuit board. Thus, for example, as shown in the figure, an intermediate printed conductor layer with printed conductors 17 can be provided, on which the ASIC substrate 8 with the ASIC device 3 embedded in the recess 15 can be electrically connected.

[0044] Figure 4a and 4b A detailed view of the microelectromechanical device 1 according to the fourth embodiment is shown schematically. Figure 4a and 4b As can be seen, the ASIC substrate 8 has edge plating 18 to enable electrical contact between the ASIC substrate 8 and the printed wiring structure of the MEMS substrate 7 at its end face. To electrically connect the edge plating 18 to the top metallization of the connection structure such as the MEMS substrate 7, the ASIC substrate 8 is attached to the MEMS substrate 7 via solder joints 14 in the region of the edge plating 18. According to the illustrated embodiment, the ASIC substrate 8 is also stabilized on the MEMS substrate 7 via adhesive joints 13.

[0045] Figure 5 A detailed diagram of the microelectromechanical device 1 according to a fifth embodiment is shown schematically. This fifth embodiment is... Figure 4a and 4b In a variation of the illustrated embodiment, the ASIC substrate 8 is partially embedded in a recess 15 of the MEMS substrate 7. The ASIC substrate 8 is electrically connected to the MEMS substrate 7 via one end face through solder connections 14 and edge metallization 18. To further stabilize the ASIC substrate 8 in the recess 15, the recess is filled with an underfill adhesive 19.

[0046] Figure 6 A microelectromechanical device 1 according to a sixth embodiment is shown schematically. The device 1 according to the sixth embodiment has a support structure 4, which is configured as a MID circuit carrier 9. This allows for the creation of a compact device 1 with high mechanical protection for the MEMS devices and ASIC devices 2, 3 fixed to the support structure 4, wherein the MID circuit carrier 9 has high configurational and shape freedom in its mechanical and electrical structures and their relative arrangement. Thus, the device 1 can be individually adapted to pre-defined product or process requirements.

[0047] The MID circuit carrier 9 has two opposing inlets 5. A MEMS device 2 is embedded in a recess 15 between these inlets and fixed to a first surface 6a of the MID circuit carrier 9 by an adhesive connection 13. The inlets 5 can, for example, form the front and rear cavity volumes of the acoustic MEMS device 2. An ASIC device 3 is embedded in another recess 15 and fixed to a second surface 6b of the MID circuit carrier 9, which extends substantially orthogonally to the first surface 6a. The ASIC device 3 is fixed to the second surface 6b by a solder connection 14 and electrically connected to a connection structure (not shown) of the MID circuit carrier 9. An additional underfill 19 supports, protects, and seals the attachment of the ASIC device 3 to the second surface 6b. The MEMS device 2 is electrically connected to the connection structure (not shown) of the MID circuit carrier 9 via lead bridge contacts 12. As a connection structure, the MID circuit carrier 9 may have printed conductors, for example, generated during the manufacture of the MID circuit carrier 9 according to a predetermined three-dimensional circuit layout. Therefore, according to the embodiment shown, the MEMS device 2 and the ASIC device 3 are indirectly electrically connected to each other via the carrier structure 4. The MID circuit carrier 9 can be connected to a circuit board of a higher-level system, for example, via the electrical contact structure 11 on the carrier structure side 4a away from the devices 2 and 3.

[0048] exist Figure 6 It can also be seen that, according to the illustrated embodiment, the width b of the ASIC device 3 ABasically corresponding to the height h of MEMS device 2 M Therefore, even when devices 2 and 3 are orthogonally oriented, a compact device 1 can be provided.

[0049] Figure 7 The microelectromechanical device 1 according to the seventh embodiment is shown schematically. This seventh embodiment differs from the sixth embodiment in the attachment of the MEMS device 2 to the first surface 6a of the MID circuit carrier 9. Therefore, here, the adhesive connection 13 is supplemented by a brazed connection 14 between the MEMS device 2 and the carrier structure 4, thereby combining high mechanical stability and sealing with electrical conductivity at the connection point through the brazed connection 14. Thus, for example, the lead bridge contacts 12 used in the sixth embodiment can be omitted.

[0050] Figure 8 The microelectromechanical device 1 according to the eighth embodiment is shown schematically. This eighth embodiment differs from the sixth embodiment in the attachment of the ASIC device 3 to the MID circuit carrier 9. Instead of the solder connection 14 and the underfill 19, the attachment is provided only by the underfill 19, and the electrical connection between the ASIC device 3 and the MID circuit carrier 9 (not shown) is achieved by the lead bridge contact 12.

[0051] Figure 9 The microelectromechanical device 1 according to the ninth embodiment is shown schematically. The ninth embodiment corresponds to a combination of the seventh and eighth embodiments. Here, the MEMS device 2 is attached to the MID circuit carrier 9 by adhesive connection 13 and solder connection 14, while the ASIC device 3 is locked to the second surface 6b material of the MID circuit carrier 9 by underfill 19 and electrically contacted by lead bridge contacts 12.

[0052] Figure 10 The microelectromechanical device 1 according to the tenth embodiment is shown schematically. The tenth embodiment differs from the sixth embodiment in that the electrical contact structure 11 is not arranged on the support structure side 4a forming the lower side of the support structure 4, but rather on the support structure side 4a forming the upper side of the support structure 4. For example, the lower side of the support structure 4 may be closer to the first surface 6a on which the MEMS device 2 is fixed than the upper side of the support structure 4. The arrangement of the electrical contact structure 11 can be selected differently, for example, depending on the application purpose of the device 1 or the intended installation.

[0053] Figure 11 A microelectromechanical device 1 according to the eleventh embodiment is shown schematically. The eleventh embodiment differs from the sixth embodiment in that the device 1 has a protective diaphragm 16 for protecting the device 1 from particles and / or moisture. Figure 11As shown, the protective diaphragm 16 can be arranged, for example, on the upper side of the supporting structure 4, and advantageously in the recessed portion 20 of the supporting structure 4. Thus, the protective diaphragm 16 is mechanically protected and can be easily fixed to the supporting structure 4.

[0054] Figure 12 The microelectromechanical device 1 according to the twelfth embodiment is shown schematically. The device 1 according to the twelfth embodiment has a support structure 4 configured as an additively manufactured layered circuit carrier 10. This allows for the direct creation of a support structure 4 individually adapted to MEMS devices and ASIC devices 2, 3 during layer construction, possessing desired mechanical and electrical structures. Furthermore, a protective diaphragm 16 can be integrated during layer construction, which can be mechanically stabilized, for example, by a support structure 21. Figure 12 As seen, apart from the two opposing inlets 5, the MEMS device 2 is embedded or encapsulated within the layered structure of the layered circuit carrier 10, thereby reliably sealing it and preventing, for example, acoustic leakage paths between the front and rear cavity volumes formed through the inlets 5. The layered structure forms a housing structure to protect the device 1 from mechanical forces and undesirable environmental influences such as particle and liquid ingress. According to the twelfth embodiment, the MEMS device 2 is fixed to a first surface 6a of the carrier structure 4, which may be, for example, the surface of a layer formed during the layered construction and is also framed by other layers of the layered structure. The ASIC device 3 is fixed to a second surface 6b of the carrier structure 4, which is formed by the lateral layer boundaries of the layered structure and is also framed by other layers of the layered structure. For external contact of the device 1, an electrical contact structure 11 is provided on the outer carrier side 4a of the carrier structure 4.

[0055] Figure 13 A simplified flowchart of a method 100 for manufacturing a microelectromechanical device 1 is shown schematically. According to... Figure 13 Method 100 includes the following steps: In the first step 110, MEMS device 2 and ASIC device 3 are provided; In the second step 120, a load-bearing structure 4 with an inlet 5 is provided or generated; In the third step 130, the MEMS device 2 is fixed to the first surface 6a of the support structure 4, such that the MEMS device 2 spans the inlet 5; and In the fourth step 140, the ASIC device 3 is fixed on the 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.

[0056] As illustrated by the first to twelfth embodiments, a MEMS substrate 7 and an ASIC substrate 8 can be provided as a carrier structure 4 and interconnected thereto, wherein the ASIC substrate 8 is arranged substantially orthogonally to the MEMS substrate 7. Alternatively, the carrier structure 4 can be provided as a MID circuit carrier 9 or produced as a layered circuit carrier 10 using additive manufacturing methods.

[0057] By utilizing the microelectromechanical device 1 proposed according to the above embodiments and by means of the method 100 for manufacturing the device 1, a compact, space-optimized, robust and easy-to-manufacture microelectromechanical device 1 can be provided.

Claims

1. A microelectromechanical device (1) comprising a MEMS device (2) and an ASIC device (3), wherein the devices are fixed on a support structure (4) of the device (1), wherein, The support structure (4) has an inlet (5) adjacent to the MEMS device (2), and wherein the MEMS device (2) is fixed on a first surface (6a) of the support structure (4), and the ASIC device (3) is fixed on 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. The apparatus (1) according to claim 1, wherein, The support structure (4) has a MEMS substrate (7), the MEMS device (2) is fixed on the MEMS substrate, and wherein the support structure (4) has an ASIC substrate (8) arranged substantially orthogonally to the MEMS substrate (7), the ASIC device (3) is fixed on the ASIC substrate.

3. The apparatus (1) according to claim 1, wherein, The supporting structure (4) is the MID circuit carrier (9).

4. The apparatus (1) according to claim 1, wherein, The supporting structure (4) is an additively manufactured layered circuit carrier (10).

5. The apparatus (1) according to any one of the preceding claims, wherein, The support structure (4) has an electrical contact structure (11) on the support structure side (4a) away from the MEMS device (2) and the ASIC device (3).

6. The apparatus (1) according to any one of the preceding claims, wherein, The MEMS device (2) and the ASIC device (3) are electrically connected to each other through at least one lead bridge contact (12).

7. The apparatus (1) according to any one of the preceding claims, wherein, The MEMS device (2) and / or the ASIC device (3) are connected to the support structure (4) by means of adhesive connection (13).

8. The apparatus (1) according to any one of the preceding claims, wherein, The MEMS device (2) and / or the ASIC device (3) are connected to the support structure (4) by means of a solder connection (14).

9. The apparatus (1) according to any one of the preceding claims, wherein, The support structure (4) has at least one recess (15), and the MEMS device (2) and / or the ASIC device (3) extend into the recess at least in sections.

10. The apparatus (1) according to any one of the preceding claims, wherein, The ASIC device (3) has a width (b A The width is approximately the same as the height (h) of the MEMS device (2). M ).

11. The apparatus (1) according to any one of the preceding claims, wherein, A protective diaphragm (16) is arranged on the load-bearing structure (4).

12. The apparatus (1) according to any one of the preceding claims, wherein, The device (1) is constructed as an acoustic transducer.

13. A method (100) for manufacturing a microelectromechanical device (1), comprising the following steps: MEMS devices (2) and ASIC devices (3) (110) are provided; Provide or generate a load-bearing structure (4) (120) with an inlet (5); The MEMS device (2) is fixed to the first surface (6a) of the support structure (4) such that the MEMS device (2) spans the inlet (5) (130); and The ASIC device (3) is fixed on the second surface (6b) (140) of the support structure (4), wherein, The second surface (6b) is oriented substantially orthogonal to the first surface (6a) of the supporting structure (4).

14. The method according to claim 13, wherein, A MEMS substrate (7) and an ASIC substrate (8) are provided as a support structure (4) and interconnected, wherein the ASIC substrate (8) is arranged substantially orthogonally to the MEMS substrate (7).

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

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

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