Signal-transmitting structure for a vehicle module, vehicle module, comprising a signal-transmitting structure and method for manufacturing the signal-transmitting structure

Abstract

A signal-transmitting structure 245 for a vehicle module is proposed, comprising: a case 200, a signal-transmitting area 205, which is arranged on the housing 200, a MEMS transceiver unit 235, for transmitting a signal, in particular an ultrasound signal, and for receiving a reflected signal, in particular a reflected ultrasound signal, a connection unit 210, which is arranged between the signal-transmitting area 205 and the MEMS transceiver unit 235, for connecting the signal-transmitting area 205 with the MEMS transceiver unit 235, wherein the connecting unit 210 comprises a switchable material whose dynamic-mechanical properties can be selectively controlled by the action of an external field 280, in particular a magnetic field 285, to adjust the stiffness of the connection between the signal-transmitting area 205 and the MEMS transceiver unit 235.

Description

[0001] The invention relates to a signal-transmitting structure for a vehicle module. Furthermore, the invention relates to a vehicle module comprising a signal-transmitting structure, as well as to a method for producing the signal-transmitting structure. State of the art

[0002] A signal-transmitting structure for transmitting and receiving ultrasonic signals, as well as a method for its production, are known from US Pat. No. 11,181,627 B2. However, the signal-transmitting structure of the aforementioned document is designed without a connecting unit with switchable material for the targeted adjustment of the stiffness between the signal-transmitting region 214 and the MEMS signal unit 22, 222.

[0003] The object of the invention is to provide an improved signal-transmitting structure for a vehicle module that is robust against external mechanical influences and also offers the required sensitivity. Furthermore, the object of the invention is to provide an improved method for producing said signal-transmitting structure and an optimized vehicle module comprising the signal-transmitting structure.

[0004] This object is achieved by the independent claims. Further advantageous embodiments of the invention are the subject of the dependent claims. Disclosure of the invention

[0005] A signal-transmitting structure for a vehicle module is proposed. The signal-transmitting structure comprises: a housing, a signal-transmitting area arranged on the housing, a MEMS transceiver unit for transmitting a signal, in particular an ultrasonic signal, and for receiving a reflected signal, in particular a reflected ultrasonic signal, a connection unit arranged between the signal-transmitting region and the MEMS transceiver unit for connecting the signal-transmitting region to the MEMS transceiver unit, The connecting unit comprises a switchable material whose dynamic mechanical properties can be specifically controlled by the action of an external field, in particular a magnetic field, to adjust the stiffness of the connection between the signal-transmitting region and the MEMS transceiver unit. The external field can, for example, form an electric field or a magnetic field.

[0006] The variable dynamic-mechanical property for adjusting the stiffness of the connection between the signal-transmitting area and the MEMS transceiver unit is achieved by changing the elastic modulus (E-modulus) of the switchable material. The E-modulus can be specifically varied by applying an external field, with a first switching state describing a state without an external field acting on the switchable material. The switchable material is therefore in the neutral state, with the E-modulus being low in this state (compared to the second switching state; as a guideline, a difference of at least two orders of magnitude in the E-modulus between the two switching states is desirable), for example, on the order of a few tens of MPa.

[0007] The connection between the signal-transmitting area and the MEMS transceiver unit is designed to be decoupling in the first switching state. This means that it can be considered a flexible, soft connection that protects against external influences, such as stone chips, since it is not designed to transmit shocks.

[0008] A second switching state describes a state in which an external field acts on the switchable material. The elastic modulus of the switchable material can be high compared to the elastic modulus of the first switching state, amounting to several GPa. The connection between the signal-transmitting region and the MEMS transceiver unit is designed to be coupled in the second switching state, meaning it can be considered a stiff, i.e., rigid, connection and thus act to transmit signals.

[0009] In addition, a method for producing the above-mentioned signal-transmitting structure is proposed. The method comprises the following steps: Providing a housing and a signal-transmitting area arranged on the housing as well as a connection unit in a first step, wherein the connecting unit comprises a switchable material whose dynamic-mechanical properties can be specifically controlled by the action of an external field, in particular a magnetic field, for adjusting a stiffness of a connection between the signal-transmitting region of the signal-transmitting structure and a MEMS transceiver unit, Providing a circuit board comprising the MEMS transceiver unit and a field generating element for providing the external field, in particular magnetic field, in a second step, Establishing the connection between the signal-transmitting area of ​​the signal-transmitting structure and the MEMS transceiver unit in a third step by joining the circuit board into the housing of the signal-transmitting structure, and Closing the housing of the signal-transmitting structure in a fourth step.

[0010] Furthermore, a vehicle module for use in a front and / or rear vehicle area of ​​a vehicle is proposed. The vehicle module is designed in particular as a distance sensor and comprises: a signal-transmitting structure mentioned above, wherein the vehicle module is deactivated in a first operating state, provided that the first switching state for the switchable material of the connection unit is present, wherein the vehicle module is activated in a second operating state, provided that the second switching state for the switchable material of the connection unit is present, wherein the first operating state in particular forms a movement of the vehicle at a first speed and the second operating state in particular forms a movement of the vehicle at a second speed, wherein the first speed is greater than the second speed, and a control unit for controlling the MEMS transceiver unit of the signal-transmitting structure and / or evaluating the signals of the MEMS transceiver unit of the signal-transmitting structure and / or for applying an electrical voltage to the field-generating element to implement the second switching state of the switchable material.

[0011] Currently, piezoceramic-based transceiver units (as ultrasonic transceiver units) are commonly used, which are mounted on printed circuit boards using conventional SMD (surface-mounted device) technology. The assembled circuit boards are typically positioned within a plastic injection-molded housing, which can be supplemented, for example, by locally inserted metal caps in the area used for ultrasonic signal transmission.

[0012] In current piezoceramic-based systems, which are also limited to one transceiver unit per housing part (i.e.: arrays of transceiver units in the same housing of the signal-transmitting structure are not possible), the conflict of objectives between mechanical robustness and sensitivity is solved by the fact that the one transceiver unit is not in direct contact with the (compliantly designed) signal-transmitting area of ​​the housing, and the space between is filled with a potting compound whose rheological properties are selected in such a way that ultrasonic signal transmission is possible, but mechanical influences from outside, such as stone chips or similar, do not usually lead to damage to the transceiver unit.

[0013] However, for the proposed signal-transmitting structure comprising a MEMS transceiver unit (as well as the associated manufacturing process and the vehicle module comprising the signal-transmitting structure), the solution using a potting compound is not feasible, as the MEMS transceiver unit must be in substantially direct contact with the signal-transmitting area of ​​the signal-transmitting structure's housing. "Substantially in direct contact" can mean that the MEMS transceiver unit is in direct contact with the signal-transmitting area of ​​the signal-transmitting structure's housing via a proposed connection unit.

[0014] Likewise, if more than one MEMS transceiver unit can be used per package, essentially direct contact between the MEMS transceiver units and the signal-transmitting areas of the signal-transmitting structure is necessary. Otherwise, unwanted signal interference would occur between the signals of different MEMS transceiver units.

[0015] The proposed signal-transmitting structure, comprising the MEMS transceiver unit, advantageously protects the sensitive MEMS transceiver unit from external mechanical impact (stone impact or similar) and provides the required sensitivity.

[0016] The proposed signal-transmitting structure features the proposed connection unit with the switchable material. This switchable material allows the stiffness of the connection between the MEMS transceiver unit and the signal-transmitting area of ​​the signal-transmitting structure's housing to be specifically adjusted according to the current requirements, i.e., the operating conditions of the vehicle module (preferably designed as a distance sensor): • During the first operating state of the vehicle module (first switching state of the switchable material of the connection unit), i.e., when the vehicle is moving at the first speed (at high speed, e.g., driving on the highway or similar), the vehicle module configured as a distance sensor is not used (deactivated vehicle module), and therefore no precise, rigid connection of the MEMS transceiver unit to the signal-transmitting area of ​​the housing of the signal-transmitting structure is necessary. Therefore, the precise connection in the first operating state is advantageously set to be soft (i.e., compliant, and therefore decoupling), so that stone chips or similar impacts hitting the housing of the signal-transmitting structure at high speed do not damage the MEMS transceiver unit. • During the second operating state of the vehicle module (second switching state of the switchable material of the connection unit), i.e. when the vehicle is moving at the second speed (at a lower speed compared to the first speed, e.g., when parking, etc.), the vehicle module designed as a distance sensor is in use (vehicle module activated) and must therefore have a precisely fitting, rigid connection of the MEMS transceiver unit to the signal-transmitting area of ​​the housing of the signal-transmitting structure in order to be able to measure precisely. In the second operating state, the rigid connection is unproblematic with regard to the mechanical robustness of the signal-transmitting structure, since only low relative speeds are effective and rockfall or similar impacts do not have to be expected.In the second operating mode, the focus is on the actual measurement operation (sensitivity), i.e., the transmission and reception of signals, i.e., ultrasonic signals, by the MEMS transceiver unit via the connection unit and the signal-transmitting area to the environment, and vice versa. The MEMS transceiver unit can, for example, be modulated every 10 ms for transmission or reception.

[0017] To provide the different operating modes and switching states, a material is used for the connecting unit whose dynamic mechanical properties can be specifically modified by applying an external field, e.g., a magnetic field. Materials exhibiting this property include magnetorheological materials. A connecting piece can be manufactured from this material that connects the MEMS transceiver unit (or the plurality of MEMS transceiver units in an array implementation) precisely, i.e., flush, with the respective signal-transmitting area of ​​the housing.

[0018] Since the second operating state, in which the vehicle module designed as a distance sensor is used, is significantly shorter in time than the first operating state, in which the vehicle module designed as a distance sensor is not used, it seems sensible to design the switchable material, e.g. the magnetorheological material, of the connecting unit such that it is soft in the neutral state (i.e. without a generated external field, e.g. a magnetic field). As a component for generating a static external field, e.g. a magnetic field, which can be selectively switchable over time, a field generating element, e.g. an electrical conductor, which can be designed as a coil, can be used to generate the field, e.g. a magnetic field, by means of which the field, e.g. a magnetic field, can be generated by means of an adjustable electrical current flow, wherein the field, e.g. a magnetic field, can be variably adjustable in relation to the temporal progression and / or the field strength.It is understood that a permanent magnetic field would not be suitable due to the lack of switchability required to implement the above-mentioned operating modes and switching states.

[0019] The key advantage of the invention is therefore that it resolves the trade-off between sensitivity and mechanical robustness. This allows for the realization of a MEMS transceiver unit with a precise, i.e., flush, connection to the signal-transmitting area of ​​the housing, without the risk of damage to the MEMS transceiver unit, which could otherwise occur in the initial operating state, in which the use of the vehicle module designed as a distance sensor is not intended.

[0020] In addition, further advantages are conceivable that can be achieved through the targeted, time-variable adjustability of the dynamic-mechanical properties of the switchable material of the connection unit between the MEMS transceiver unit and the signal-transmitting area of ​​the housing of the signal-transmitting structure: • Faster decay of the MEMS oscillation at the end of the signal transmission process, for subsequent rapid switching to the signal reception mode of the MEMS transceiver unit: By momentarily setting a high attenuation of the switchable material of the connection unit, the decay (logarithmic decrement) can be increased. By quickly switching (e.g., every 10 ms) the MEMS transceiver unit from transmission mode to reception mode, shorter minimum distances to the object to be detected can be achieved (signal propagation time from the vehicle module designed as a distance sensor to the object to be detected and back ≥ switching time from transmission mode to reception mode).

[0021] Alternatively, a design of the vehicle module as a lane change assistant would also be conceivable, for example, where the blind spot can be monitored in the vehicle's rearview mirror and, if necessary, a warning signal can be displayed to the driver if another vehicle is in the adjacent lane. A lane change assistant is also operated using ultrasonic signals (approximately 1 to 2 m range) and can incorporate the proposed signal-transmitting structure.

[0022] Advantageously, the proposed signal-transmitting structure can be manufactured in a variable manner, as will be explained below.

[0023] In a further embodiment, the switchable material of the connecting unit is formed as at least one of the following materials: a magnetorheological material, in particular a magnetorheological elastomer; a switchable composite material (so-called "smart materials"), in particular a ferrofluid. Other switchable materials are also conceivable as alternatives. This advantageously resolves the conflict between mechanical robustness and sensitivity, providing the two operating modes of the vehicle module.

[0024] In a further embodiment, a first switching state describes a state without an external field acting on the switchable material of the connecting unit, in particular a magnetic field. The switchable material of the connecting unit comprises particles whose position and / or orientation within the surrounding material, in particular matrix material, is designed to be specifically changed by an external field acting on it. Without an external field acting on it, the position and / or orientation of the particles are randomly oriented in the switchable material in the first switching state and bring about a decoupling, i.e., soft, connection between the signal-transmitting region and the MEMS transceiver unit. This advantageously makes it possible to provide the neutral state of the switchable material of the connecting unit, thus enabling the first operating mode of the vehicle module to be implemented.

[0025] A decoupling connection can be understood as a dynamic-mechanical decoupling connection, i.e. a flexible connection that protects against external influences such as stone chips because it is not designed to transmit shock. The dynamic-mechanical decoupling connection is formed between the MEMS transceiver unit and the housing and, in the first switching state, comprises a state of low rigidity, i.e., is flexible or soft. The elastic modulus of the switchable material is changed to set the first and second switching states. In the first switching state, the switchable material has a low elastic modulus (compared to the second switching state; as a guideline, a difference of at least 2 orders of magnitude is desirable). For example, the elastic modulus of the switchable material in the first switching state can be on the order of a few tens of MPa.

[0026] In a further embodiment, a second switching state describes a state with an external field, in particular a magnetic field, acting on the switchable material of the connecting unit. The switchable material of the connecting unit comprises particles whose position and / or orientation within the surrounding material, in particular matrix material, is designed to be specifically changeable by an external field. The position and / or orientation of the particles are aligned in the switchable material under the influence of an external field in the second switching state and bring about a coupling, i.e., rigid, connection between the signal-transmitting region and the MEMS transceiver unit. This advantageously enables the second operating mode of the vehicle module, i.e., the active state of the vehicle module, to be implemented.The Young's modulus of the switchable material can be high for the second switching state compared to the Young's modulus of the first switching state, amounting to several GPa. The connection between the signal-transmitting region and the MEMS transceiver unit is designed to be coupled in the second switching state. This means that it can be considered a stiff, i.e., rigid connection, and thus act as a signal-transmitting element.

[0027] In a further embodiment, the second switching state is brought about by applying an electrical voltage to a field-generating element. The field-generating element is designed as an electrical conductor arranged between a circuit board on which the MEMS transceiver unit is arranged and the housing of the signal-transmitting structure. Additionally or alternatively, the electrical conductor is integrated into the circuit board on which the MEMS transceiver unit is arranged. Advantageously, the electrical conductor(s) can form coil-like, switchable current paths that are already integrated into the circuit board. Additionally or alternatively, the electrical conductor is integrated into the MEMS transceiver unit. The associated arrangement of the MEMS transceiver unit and the field-generating element in the various possible embodiments mentioned above can be constructed, for example, by SMD assembly on the circuit board as a circuit carrier.This allows the signal-transmitting structure to be provided as cost-effectively and efficiently as possible and to be flexibly adapted to requirements.

[0028] In a further embodiment, the field-generating element configured as an electrical conductor is designed as a coil. The field-generating element configured as a coil is designed to accommodate at least the MEMS transceiver unit and / or the connecting unit within the coil. In the second switching state, the coil generates a magnetic field that aligns the position and / or orientation of the particles of the switchable material of the connecting unit and creates a coupling, i.e., rigid, connection between the signal-transmitting region and the MEMS transceiver unit.

[0029] The coil can be designed, for example, in the form of a helical coil, i.e., a cylindrical coil with a helical coil wire, in order to create an approximately homogeneous, uniaxial magnetic field inside the coil. Alternatively, other coil cross-sections and geometries are conceivable. In both transmit mode and receive mode of the MEMS transceiver unit (second switching state or second operating mode), the coil, as a field-generating element, is designed with current flowing through it. This allows the signal-transmitting structure to be provided as cost-effectively, compactly, and efficiently as possible, and to be flexibly adapted to requirements.

[0030] In a further embodiment, the provision of the housing and the signal-transmitting region, as well as the connecting unit, in the first step comprises producing the housing, the signal-transmitting region, and the connecting unit by means of multi-component injection molding, in particular by means of injection-compression molding. The housing and the signal-transmitting region are made of a first material, in particular of thermoplastic. The switchable material of the connecting unit forms a second material, which is injection-molded onto the signal-transmitting region.

[0031] Advantageously, connecting units made of the switchable material, e.g., magnetorheological elastomer, can be locally molded onto the housing and the signal-transmitting area(s) as a second component. The shape of the respective connecting units is advantageously selected (e.g., conical from the signal-transmitting area to the MEMS transceiver unit, or similar) to enable a favorable joining geometry to the respective MEMS transceiver unit in a subsequent assembly step.

[0032] In a further embodiment, the provision of the housing and the signal-transmitting region, as well as the connecting unit, in the first step comprises a first and a second intermediate step, each of which can be carried out independently of one another. The housing and the signal-transmitting region are manufactured by injection molding, in particular by injection-compression molding, in the first intermediate step. The connecting unit is manufactured from the switchable material in the second intermediate step.

[0033] Instead of two-component injection molding to produce the housing, the signal-transmitting area, and the switchable material of the connecting unit as a second component, these components can also be manufactured independently of one another and joined in a later joining step. The proposed process thus advantageously offers the greatest possible flexibility in implementation.

[0034] In a further embodiment, establishing the connection between the signal-transmitting region of the signal-transmitting structure and the MEMS transceiver unit in the third step comprises establishing a first connection point between the housing and the printed circuit board by means of a first adhesive, in particular a UV-curing adhesive, and establishing a second connection point by means of the connection unit and / or by means of a second adhesive, in particular a thermally curing adhesive, between the signal-transmitting region and the MEMS transceiver unit.

[0035] The assembly of the populated circuit board into the 2K housing of the signal-transmitting structure, or alternatively, the independently manufactured components, is advantageously carried out by adhesive bonding. It seems sensible to bond the housing to the circuit board using the UV-curing first adhesive due to its rapid curing and thus stable first connection point.

[0036] In a further embodiment, the second adhesive comprises spacer elements (so-called "spacer balls") for adjusting the thickness of the second connection point. If the second adhesive is not used to create the second connection point, the thickness of the second connection point is adjusted using the switchable material of the connection unit.

[0037] For contacting the housing-side connector, i.e., the signal-transmitting area, to the oscillating structure of the MEMS transceiver unit, it is conceivable to use a thermally curing second adhesive, which may include the aforementioned spacers for spacing adjustment. Alternatively, it is also conceivable to make direct contact without an adhesive layer of the second adhesive there, since the switchable material of the connector unit, e.g., as a magnetorheological connector, is a viscoelastic component that can advantageously self-level to the required thickness through deformation during the joining process.

[0038] The above-described properties, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more readily understood in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the schematic drawings. They show: Fig. 1 is a schematic representation of a vehicle having a proposed vehicle module; Fig. 2 a schematic representation of a housing of a proposed signal transmitting structure; Fig. 3 a schematic representation of a circuit board on which a MEMS-MEMS transceiver unit is arranged as well as a field generating element; Fig. 4 a schematic representation of a proposed signal transmitting structure; Fig. 5 a schematic representation of a first switching state of a switchable material of a connecting unit of the proposed signal-transmitting structure; Fig. 6 a schematic representation of a second switching state of a switchable material of a connecting unit of the proposed signal-transmitting structure; Fig. 7 is a schematic representation of a method for manufacturing the proposed signal-transmitting structure according to a first embodiment; and Fig. 8 a schematic representation of a method for producing the proposed signal-transmitting structure according to a second embodiment.

[0039] Please note that the figures are merely schematic and not to scale. Therefore, components and elements shown in the figures may be exaggerated or reduced in size for clarity. Furthermore, please note that the reference numerals in the figures have been chosen to be unchanged or similar when referring to identical or similarly designed elements and / or components.

[0040] Fig. 1 shows a schematic representation of a vehicle 100 having a proposed vehicle module 105. The vehicle module 105 can be used in a front vehicle area 110 and / or in a rear vehicle area 115. Specifically, the vehicle module 105 can be embedded or integrated into the bumper in the front vehicle area 110. The same applies to the bumper of the rear vehicle area 115 (not shown). Alternatively, different body parts of the vehicle 100 adjacent to the bumper are also conceivable for integrating the vehicle module 105. The vehicle module 105 can be designed as a distance sensor or as a so-called parking pilot to provide the driver with information about the distance of the vehicle 100 to obstacles in the surroundings of the vehicle 100 when parking. For this purpose, the vehicle module 105 can have a surface facing the surroundings of the vehicle 100 (the outside world) (which can be designed as a housing surface).

[0041] Alternatively, for example, a configuration of the vehicle module 105 as a lane change assistant would also be conceivable, in which the blind spot can be monitored in the rearview mirror of the vehicle 100 and, if necessary, a warning signal can be displayed to the driver if another vehicle is in the adjacent lane. A lane change assistant is also operated using ultrasonic signals (approximately 1 to 2 m range).

[0042] The operating principle of the vehicle module 105 is typically based on a time-of-flight measurement of an emitted signal 120, which in the case of a distance sensor is embodied as an ultrasonic signal 125 or an acoustic signal in the ultrasonic range. At the start of a distance measurement, an ultrasonic signal is emitted by a MEMS transceiver unit (not shown) of a signal-transmitting structure comprising the vehicle module 105 through a surface facing the surroundings or outside world of the vehicle 100. If this signal 120, 125 encounters an obstacle, this results in a reflection 130, 135 of the signal. The reflected signal 130 or the reflected ultrasonic signal 135 can be detected by the MEMS transceiver unit. From the time interval between the transmission and reception of the aforementioned signals 120, 125, 130, 135, the distance to the obstacle can be calculated using the known speed of sound.The MEMS transceiver unit is designed as a microelectromechanical structure (MEMS: micro electromechanical system).

[0043] The vehicle module 105 has the signal-transmitting structure (not shown), which can be selectively elasto-mechanically designed and functionally interacts with the comprehensive MEMS transceiver unit. The signal-transmitting structure can have the above-mentioned surface facing the environment or the outside world of the vehicle 100. The vehicle module 105 can also have a control unit (not shown) for controlling and evaluating the signals from the MEMS transceiver unit. Furthermore, the control unit can be configured to apply an electrical voltage to the field-generating element to implement a second switching state of the switchable material of the connecting unit of the signal-transmitting structure, i.e., to generate an external field, e.g., a magnetic field or an electric field, etc. The control unit can also be functionally embedded or integrated into the MEMS transceiver unit.

[0044] In a first operating state of the vehicle module 105, the vehicle module 105 can be deactivated if a first switching state for a switchable material of a connecting unit of the signal-transmitting structure of the vehicle module 105 is present. The first switching state or the first operating state of the vehicle module 105 is, for example, in Fig. 5 and will be explained in more detail later. In a second operating state, the vehicle module 105 can be activated if a second switching state exists for the switchable material of the connection unit. The second switching state or the second operating state of the vehicle module 105 is shown, for example, in Fig. 6 and will be explained in more detail later.

[0045] The first operating state can be characterized in particular by a movement of the vehicle 100 at a first speed (i.e. a first speed to which the vehicle module 105 is exposed), and the second operating state can be characterized in particular by a movement of the vehicle 100 at a second speed (i.e. a second speed to which the vehicle module 105 is exposed). In this case, the first speed can in particular be greater than the second speed. For example, the first operating state or the first switching state can be a movement of the vehicle 100 at high speed on the motorway. The vehicle module 105 or the distance sensor is therefore not required. The second operating state or the second switching state can, for example, be a movement of the vehicle 100 at a lower speed compared to the first operating state, e.g. during a parking maneuver.Here, the vehicle module 105, i.e. the distance sensor, is used in the active state.

[0046] The following are the Fig. 2, Fig. 3, Fig. 4 and Fig. 7 described together. Fig. 2 shows a schematic representation of a housing 200 of a proposed signal transmitting structure. Fig. 3 shows a schematic representation of a circuit board 215 on which a MEMS-MEMS transceiver unit 235 and a field generating element 220 are arranged. Fig. 4 shows a schematic representation of a proposed signal transmitting structure 245 for the vehicle module 105 described above and Fig. 7 shows a schematic representation of a method 300 for producing the proposed signal-transmitting structure 245 according to a first embodiment.

[0047] The signal-transmitting structure 245 in Fig. 4 comprises a housing 200 and a signal-transmitting region 205 arranged on the housing 200. The housing 200 can form a substantially closed frame-like structure, i.e., an at least approximately closed frame-like structure or a completely closed frame-like structure. The housing can have a first wall thickness. The signal-transmitting region 205 can have a second wall thickness (neither shown).

[0048] The signal-transmitting structure 205 also includes at least one signal-decoupling element (not shown), which is designed to be movable and may have a third wall thickness. The signal-decoupling element is arranged at least circumferentially around the signal-transmitting region 205 and at least partially borders the frame-like structure of the housing 200. The third wall thickness of the signal-decoupling element may be smaller than the first and / or second wall thickness.

[0049] Advantageously, by using the signal-decoupling element, unwanted signal interference can be avoided and thus the signal quality of the proposed signal-transmitting structure 205 can be optimized. The signal-decoupling element can be designed, for example, as a web element or as a foil element or a foil.

[0050] The coupling of the transmitted signal (as well as the coupling of the signal reflected by the environment) occurs through the deflection of the housing surface intended for this purpose. This deflection is stimulated by the respective ultrasonic signal. To ensure sufficiently good signal transmission even with weak ultrasonic signals, the signal-transmitting housing part (the signal-transmitting area 205) must be flexibly connected (via a signal-decoupling element) to the rest of the housing 200 (the frame-like structure of the housing), which requires a design with low rigidity (at least locally). This can be advantageously achieved by the proposed different wall thicknesses for the aforementioned areas.By selecting a smaller third wall thickness for the signal-decoupling element, in comparison to the larger second wall thickness for the signal-transmitting region 205 and the larger first wall thickness for the adjacent at least frame-like structure of the housing 200, mobility of the signal-transmitting housing part relative to the frame-like structure of the housing can advantageously be achieved, while at the same time providing the frame-like structure of the housing with the required rigidity (robust construction).

[0051] Furthermore, the signal-transmitting structure 245 comprises the MEMS transceiver unit 235 for transmitting a signal, in particular an ultrasonic signal, and for receiving a reflected signal, in particular a reflected ultrasonic signal. The principle is as explained by Fig. 1. An active oscillatory structure of the MEMS transceiver unit 235 is schematically shown with the reference numeral 240 in Fig. 4 indicated.

[0052] In addition, the signal-transmitting structure 245 comprises a connection unit 210 arranged between the signal-transmitting region 205 and the MEMS transceiver unit 235 for connecting the signal-transmitting region 205 to the MEMS transceiver unit 235.

[0053] It is understood that the shape or geometry of the signal-transmitting region 205, the oscillatable structure 240 of the MEMS transceiver unit 235, the MEMS transceiver unit 235, and the connection unit 210 is exemplary in nature and can also be implemented differently in an alternative embodiment. For example, the shape or geometry of the switchable material of the connection unit 210 can be slightly conical to better compensate for the different size ratios between the MEMS transceiver unit 235 and the housing 200 with the signal-transmitting region 205, with the conical tip oriented toward the MEMS transceiver unit 235 and the larger conical base oriented toward the signal-transmitting region 205 of the housing 200. This also applies without limitation to the following figures.

[0054] The housing 200, the signal transmitting area 205 and the connection unit 210 are in Fig. 2, for example, is also shown. The connecting unit 210 comprises a switchable material whose dynamic mechanical properties can be specifically controlled by the action of an external field, in particular a magnetic field, in order to adjust the stiffness of the connection between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0055] The switchable material of the connection unit 210 is formed as at least one of the following materials: a magnetorheological material, preferably a magnetorheological elastomer; a switchable composite material, preferably a ferrofluid. It is understood that this list is not intended to be exhaustive; alternative switchable materials can also be used, whose dynamic-mechanical properties can be specifically controlled by the action of an external field, e.g., a magnetic field, to adjust the stiffness of the connection between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0056] The variable dynamic mechanical property for adjusting the stiffness of the connection between the signal-transmitting region 205 and the MEMS transceiver unit 235 is achieved by changing the elastic modulus (E-modulus) of the switchable material. The E-modulus can be specifically varied by applying an external field.

[0057] The connection between the signal-transmitting area and the MEMS transceiver unit is designed to be decoupling in the first switching state. This means that it can be considered a flexible, soft connection that protects against external influences, such as stone chips, since it is not designed to transmit shocks.

[0058] A first switching state (first operating state of the vehicle module 105) describes a state without an external field, in particular a magnetic field, acting on the switchable material of the connection unit 210. The switchable material is therefore in the neutral state, wherein the modulus of elasticity in this state is low (compared to the second switching state; as a guideline, a difference of at least 2 orders of magnitude in the modulus of elasticity between the two switching states is desirable), for example in the order of a few 10 MPa.

[0059] The switchable material of the connecting unit comprises particles whose position and / or orientation within the surrounding material, in particular matrix material, is designed to be specifically changeable by an external field. Without an external field, the position and / or orientation of the particles are randomly oriented in the switchable material in the first switching state and effect a decoupling connection between the signal-transmitting region 205 and the MEMS transceiver unit 235. The stiffness of the connection between the signal-transmitting region 205 and the MEMS transceiver unit 235 is therefore low in the first switching state. This is Fig. 5 shown.

[0060] A second switching state (second operating state of the vehicle module 105) describes a state with an external field, in particular a magnetic field, acting on the switchable material of the connection unit 210. The elastic modulus of the switchable material can be high compared to the elastic modulus of the first switching state and can amount to several GPa. The connection between the signal-transmitting region 205 and the MEMS transceiver unit 235 is designed to be coupled in the second switching state, ie, it can be understood as a stiff, i.e., rigid connection, and thus act to transmit signals. The position and / or location of the particles within the surrounding material, e.g.Matrix material, if the switchable material is a magnetorheological elastomer, is formed in the switchable material in an aligned manner under the influence of the external field, in particular a magnetic field, and brings about a coupling connection between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0061] The method 300 for producing the proposed signal-transmitting structure 245, with the above-mentioned components, comprises, in a first step 305, the provision of the housing 200 and the signal-transmitting region 205 arranged on the housing 200, as well as the connection unit 210. The first step 305 is shown, for example, in Fig. 2. The connecting unit 210 comprises the aforementioned switchable material, whose dynamic mechanical properties can be specifically controlled by the action of an external field, preferably a magnetic field, to adjust the stiffness of the connection between the signal-transmitting region 205 of the signal-transmitting structure 245 and the MEMS transceiver unit 235.

[0062] In a second step 310 of the method 300, a circuit board 215 comprising the MEMS transceiver unit 235 and a field generating element 220 for providing the external field, preferably the magnetic field, is provided. The second step 310 is shown, for example, in Fig. 3. In a third step 315, the connection between the signal-transmitting region 205 of the signal-transmitting structure 245 and the MEMS transceiver unit 235 is established by joining the printed circuit board 215 into the housing 200 of the signal-transmitting structure 245. The third step 315 is shown, for example, in Fig. 4. A fourth step 320 in Fig. 7 can finally represent a closure of the housing 200 of the signal-transmitting structure 245. Conventional methods can be used for this purpose, for example.

[0063] Providing the housing 200 and the signal-transmitting region 205, as well as the connecting unit 210, in the first step involves producing the housing 200, the signal-transmitting region 205, and the connecting unit 210 by means of multi-component injection molding, preferably by means of injection-compression molding. The housing 200 and the signal-transmitting region 205 are made from a first material, e.g., thermoplastic. The switchable material of the connecting unit 210 forms a second material, which is injection-molded onto the signal-transmitting region 205 of the signal-transmitting structure 245.

[0064] The establishment of the connection between the signal-transmitting region 205 of the signal-transmitting structure 245 and the MEMS transceiver unit 235 in the third step 315 (cf. Fig. 4) comprises establishing a first connection point 250 between the housing 200 and the printed circuit board 215 using a first adhesive, in particular a UV-curing adhesive. The first connection point 250 can also form a first joining point and extend circumferentially around the substantially closed frame-like structure that forms the housing 200. Furthermore, establishing the connection in the third step 315 (cf. Fig. 4) producing a second connection point 255 by means of the connection unit 210 and / or by means of a second adhesive, in particular a thermally crosslinking adhesive, between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0065] By using the first and second adhesives and / or the connecting unit 210 to create the first and second connection points 250, 255, unwanted misalignment of the components of the signal-transmitting structure 245 can be advantageously avoided and contact of the connection points 250, 255 with the desired components can be ensured. Advantageously, the crosslinking of the UV-curing first adhesive occurs more quickly than the crosslinking of the thermally crosslinking adhesive or the crosslinking of the aforementioned switchable material of the connecting unit 210, so that a stable connection, i.e., a stable contact, can initially be established between the housing 200 and the circuit board 215 in order to advantageously compensate for the static overdetermination of the system.

[0066] The second adhesive comprises spacer elements (so-called spacer balls) for adjusting the thickness of the second connection point 255. If the second adhesive is not used to produce the second connection point 255, i.e., if the second connection point 255 is formed solely by the switchable material of the connection unit 210, the thickness of the second connection point 210 is adjusted by means of the switchable material of the connection unit 210. It is understood that the switchable material of the connection unit 210 is in the first switching state, i.e., without the influence of the external field.

[0067] Fig. Figure 8 shows a schematic representation of a method 400 for manufacturing the proposed signal-transmitting structure 245 according to a second embodiment. The method 400 in Fig. 8 differs essentially from the method 300 in Fig. 7, that the provision of the housing 200 and the signal-transmitting region 205 as well as the connecting unit 210 in the first step 405 comprises a first and second intermediate step 407, 409, which can each be carried out independently of one another. The housing 200 and the signal-transmitting region 205 are produced by injection molding, in particular by injection-compression molding, in the first intermediate step 407, and the connecting unit 210 is produced from the switchable material in the second intermediate step 409. A second to fourth method step 410, 415, 420 can be similar to the second to fourth steps 310, 315, 320 in Fig. 7, therefore reference is made to the above explanation.

[0068] Fig. 5 shows a schematic representation of the first switching state 260 (first operating state 140 of the vehicle module 105 as explained above) of the switchable material of the connection unit 210 of the proposed signal-transmitting structure 205. As mentioned above, the first switching state 260 describes the state without an external field acting on the material of the connection unit 210. The field-generating element 220, which is designed as a coil 221, does not carry any current. The position and / or orientation of the particles 275, preferably designed as magnetically activatable particles, provided the external field forms a magnetic field 285, are therefore randomly oriented 277 in the switchable material of the connection unit 210. This creates a decoupling, i.e., soft, connection between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0069] The decoupling, i.e. soft, connection between the signal-transmitting area 205 and the MEMS transceiver unit 235 advantageously prevents external influences, e.g., a stone impact 270 on the housing 200, from causing damage to the signal-transmitting structure 245. The MEMS transceiver unit 235 is advantageously protected from external influences because the connecting unit 210 comprises switchable material, e.g., magnetorheological material, which in its neutral state (without external field 280) has low stiffness and effects a dynamic-mechanical decoupling between the active MEMS transceiver unit 235 and the housing 200. In other words, the elastic modulus of the connecting unit 210 is Fig. 5 advantageously small, so that the impulse in the case of stone impact 270 on the housing 200 of the signal-transmitting structure 245 is not passed on via the connecting unit 210.

[0070] Fig. 6 shows a schematic representation of the second switching state 265 of the switchable material of the connecting unit 210 of the proposed signal-transmitting structure 245. In contrast to the first switching state 260 in Fig. 5, the second switching state 265 is characterized by the state with an external field 280, preferably a magnetic field 285, acting on the switchable material of the connecting unit 210. Accordingly, the position and / or orientation of the particles 275 of the switchable material of the connecting unit (under the influence of the external field 280, in particular under the influence of a magnetic field 285) are aligned 279 in the switchable material. The alignment 279 of the position and / or orientation of the particles 275 by the acting magnetic field 285 effects a coupling, i.e., rigid, connection (a dynamic-mechanical coupling) between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0071] The second switching state 265 is brought about by applying an electrical voltage to the field-generating element 220. The field-generating element 220 is configured as an electrical conductor arranged between the circuit board 215, on which the MEMS transceiver unit 235 is arranged, and the housing 200 of the signal-transmitting structure 245. Additionally or alternatively, the electrical conductor can be integrated as a field-generating element 220 into the circuit board 215, on which the MEMS transceiver unit 235 is arranged. For example, as coil-like circuits, or the like. Additionally or alternatively, the electrical conductor (preferably configured as a coil) can be integrated as a field-generating element 220 into the MEMS transceiver unit 235.

[0072] If the field generating element 220 designed as an electrical conductor is designed as a coil 221 (in Fig. 6, the coil is current-carrying and is therefore designated by the reference numeral 222), the coil 221 is designed to accommodate at least the MEMS transceiver unit 235 and / or the connection unit 210 within the coil 221 (in the illustration in Fig. 5 (as well as in Fig. 6) the coil 221 accommodates both the MEMS transceiver unit 235 and the connection unit 210 within the coil 221. The coil 221 can be designed, for example, in the form of a helical coil, i.e. a cylindrical coil with a helical course of the coil wire, in order to form an approximately homogeneous, uniaxial magnetic field inside the coil 221. Alternatively, other coil cross-sections and geometries are conceivable. The coil 221 acts in the illustration (also applies to previous figures and following figures) in Fig. 5 is split in two merely due to the cross-sectional view. However, it is understood that the coil 221 is formed as a continuous coil. The coil can, for example, be designed in the form of a helical coil, i.e., a cylindrical coil with a helical coil wire, in order to form an approximately homogeneous, uniaxial magnetic field inside the coil. Alternatively, other coil cross-sections and geometries are conceivable.

[0073] In the second switching state 265 (second operating module 145 of the vehicle module 105), the current-carrying coil 222 generates a magnetic field 285, which effects an alignment 279 of the position and / or orientation of the magnetically activatable particles 275 of the switchable material of the connecting unit 210 and a coupling, i.e., rigid, connection between the signal-transmitting region 205 and the MEMS transceiver unit 235.

[0074] In Fig. 6, for example, shows the transmission mode of the MEMS transceiver unit 235, in which signals, ie, ultrasonic signals, are generated by the oscillating MEMS transceiver unit 235 and, via the rigid connection of the switchable material of the connection unit 210, the signal-transmitting region 205 of the housing 200 is also excited to oscillate in order to transmit the signals, ie, ultrasonic signals, into the environment. It is understood that the reception mode of the MEMS transceiver unit 235 (not shown) is similar to the illustration in Fig. 6 can be implemented, i.e. with a coil 222 also carrying current to generate the magnetic field 280 (and to maintain the second switching state 265) in order to enable a counter-directed signal transmission.

[0075] The invention has been described in detail using preferred embodiments. Instead of the described embodiments, further embodiments are conceivable, which may include further modifications or combinations of the described features. For this reason, the invention is not limited to the disclosed examples, since other variations may be derived therefrom by a person skilled in the art without departing from the scope of the invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 11 181 627 B2

[0002]

Claims

[1] A signal transmitting structure (245) for a vehicle module (105), comprising: a housing (200), a signal transmitting region (205) arranged on the housing (200), a MEMS transceiver unit (235) for transmitting a signal (120), in particular an ultrasonic signal (125), and for receiving a reflected signal (130), in particular a reflected ultrasonic signal (135), a connection unit (210) arranged between the signal-transmitting region (205) and the MEMS transceiver unit (235) for connecting the signal-transmitting region (205) to the MEMS transceiver unit (235), wherein the connecting unit (210) comprises a switchable material whose dynamic-mechanical properties can be specifically controlled by the action of an external field (280), in particular a magnetic field (285), for adjusting a stiffness of the connection between the signal-transmitting region (205) and the MEMS transceiver unit (235). [2] Signal-transmitting structure according to claim 1, wherein the switchable material of the connecting unit (210) is formed as at least one of the following materials: a magnetorheological material, in particular a magnetorheological elastomer, a switchable composite material, in particular a ferrofluid. [3] Signal transmitting structure according to claim 1 or 2, wherein a first switching state (260) describes a state without an external field (280), in particular a magnetic field (285), acting on the switchable material of the connecting unit (210), wherein the switchable material of the connecting unit (210) comprises particles (275) whose position and / or location within the surrounding material, in particular matrix material, are designed to be specifically changeable by an acting external field, wherein the position and / or location of the particles without an acting external field (280) in the first switching state (260) are randomly (277) oriented in the switchable material and bring about a decoupling, i.e. soft, connection between the signal-transmitting region (205) and the MEMS transceiver unit (235). [4] Signal-transmitting structure according to one of the preceding claims, wherein a second switching state (265) describes a state with an acting external field (280), in particular a magnetic field (285), on the switchable material of the connecting unit (210), wherein the switchable material of the connecting unit (210) comprises particles (275) whose position and / or orientation within the surrounding material, in particular matrix material, are designed to be specifically changeable by an acting external field, wherein the position and / or orientation of the particles are designed to be aligned (279) in the switchable material under the influence of an external field (280) in the second switching state (265)) and bring about a coupling, i.e. rigid, connection between the signal-transmitting region (205) and the MEMS transceiver unit (235). [5] Signal transmitting structure according to claim 4, wherein the second switching state (265) is brought about by applying an electrical voltage to a field generating element (220, 221, 222), wherein the field generating element (220, 221, 222) is designed as an electrical conductor, which is arranged between a circuit board (215) on which the MEMS transceiver unit (235) is arranged and the housing (200) of the signal-transmitting structure (205) and / or which is integrated into the circuit board (215) on which the MEMS transceiver unit (235) is arranged and / or which is integrated into the MEMS transceiver unit (235). [6] Signal transmitting structure according to claim 5, wherein the field generating element (220) designed as an electrical conductor is designed as a coil (221, 222), wherein the field generating element designed as a coil (221, 222) is designed to accommodate at least the MEMS transceiver unit (235) and / or the connecting unit (210) within the coil (221, 222), and wherein the coil (221, 222) in the second switching state (265) generates a magnetic field (285) which effects an alignment (279) of the position and / or orientation of the particles (275) of the switchable material of the connecting unit (210) and a coupling, i.e. rigid, connection between the signal-transmitting region (205) and the MEMS transceiver unit (235). [7] Vehicle module (105) for use in a front (110) and / or rear (115) vehicle area of ​​a vehicle (100), wherein the vehicle module (105) is designed in particular as a distance sensor, comprising: a signal transmitting structure (245) according to one of claims 1 to 6, wherein the vehicle module (105) is deactivated in a first operating state (140) if the first switching state (260) for the switchable material of the connecting unit (210) is present, wherein the vehicle module (105) is activated in a second operating state (145) if the second switching state (265) for the switchable material of the connecting unit (210) is present, wherein the first operating state (140) in particular forms a movement of the vehicle (100) at a first speed and the second operating state (145) in particular forms a movement of the vehicle (100) at a second speed, wherein the first speed is greater than the second speed, and a control unit for controlling the MEMS transceiver unit (235) of the signal-transmitting structure (245) and / or evaluating the signals of the MEMS transceiver unit (235) of the signal-transmitting structure (245) and / or for applying an electrical voltage to the field-generating element (220, 221, 222) to carry out the second switching state (265) of the switchable material. [8] Method (300, 400) for producing a signal-transmitting structure (245) according to one of claims 1 to 6, comprising the following steps: Providing a housing (200) and a signal-transmitting area (205) arranged on the housing (200) as well as a connection unit (210) in a first step (305, 405), wherein the connecting unit (210) comprises a switchable material whose dynamic-mechanical properties can be specifically controlled by the action of an external field (280), in particular a magnetic field (285), for adjusting a stiffness of a connection between the signal-transmitting region (205) of the signal-transmitting structure (205) and a MEMS transceiver unit (235), Providing a circuit board (215) comprising the MEMS transceiver unit (235) and a field generating element (220, 221, 222) for providing the external field (280), in particular the magnetic field (285), in a second step (310, 410), Establishing the connection between the signal-transmitting region (205) of the signal-transmitting structure (245) and the MEMS transceiver unit (235) in a third step (315, 415) by joining the printed circuit board (215) into the housing (200) of the signal-transmitting structure (245), and Closing the housing (200) of the signal-transmitting structure (245) in a fourth step (320, 420). [9] Method according to claim 8, wherein the provision of the housing (200) and the signal-transmitting region (205) as well as the connecting unit (210) in the first step (305) comprises that the housing (200), the signal-transmitting region (205) and the connecting unit (210) are produced by means of multi-component injection molding, in particular by means of injection-compression molding, wherein the housing (200) and the signal-transmitting region (205) are produced from a first material, in particular from thermoplastic, and wherein the switchable material of the connecting unit (210) forms a second material which is injection-molded onto the signal-transmitting region (205). [10] Method according to claim 8, wherein the provision of the housing (200) and the signal-transmitting region (205) as well as the connection unit (210) in the first step (405) comprises a first and a second intermediate step (407, 409), each of which can be carried out independently of one another, wherein the housing (200) and the signal-transmitting region (205) are produced by injection molding, in particular by injection-compression molding, in the first intermediate step (407), and wherein the connecting unit (210) is manufactured from the switchable material in the second intermediate step (409). [11] Method according to one of the preceding claims, wherein the establishment of the connection between the signal-transmitting region (205) of the signal-transmitting structure (245) and the MEMS transceiver unit (235) in the third step (315, 415) comprises the establishment of a first connection point (250) between the housing (200) and the printed circuit board (215) by means of a first adhesive, in particular a UV-curing adhesive, and the establishment of a second connection point (255) by means of the connection unit (210) and / or by means of a second adhesive, in particular a thermally curing adhesive, between the signal-transmitting region (205) and the MEMS transceiver unit (235). [12] Method according to claim 11, wherein the second adhesive comprises spacer elements for adjusting a thickness of the second connection point (255), wherein, if the second adhesive is not used to produce the second connection point (255), a thickness of the second connection point (255) is adjusted by means of the switchable material of the connection unit (210).

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