HK1247015B - Sound converter arrangement with mems sound converter - Google Patents

Description

Sound transducer assembly having a MEMS sound transducer

Technical Field

The present invention relates to a sound transducer assembly having a MEMS sound transducer for generating and/or acquiring sound waves in the audible wavelength spectrum, the MEMS sound transducer comprising a cavity, and an ASIC electrically conductively connected to the MEMS sound transducer. Such a sound transducer assembly can be very small and can thus be used as a loudspeaker and/or microphone, for example, in hearing instruments, headphones, mobile phones, tablet computers, and other electronic devices that offer only a small amount of installation space.

Background Art

The term MEMS stands for micro-electromechanical system. A MEMS sound transducer or MEMS microphone for generating sound is known, for example, from patent document DE 10 2012 220 819 A1. Sound generation occurs via a vibratingly supported diaphragm of the MEMS microphone. Such sound transducer assemblies are specifically designed to meet the acoustic and other requirements of each application area and consist of a large number of diverse components. The primary disadvantage of such sound transducer assemblies is their correspondingly complex production, resulting in high time and cost expenditures.

Summary of the Invention

The object of the present invention is to create a sound converter assembly which has a simple construction and can be easily produced.

The object is achieved by a sound converter assembly having the features of the invention and a method for its production.

The present invention provides a sound transducer assembly comprising a first MEMS sound transducer including a first cavity and an ASIC electrically conductively connected to the first MEMS sound transducer. A MEMS sound transducer is a microelectromechanical system used to generate and/or acquire sound waves within the audible wavelength spectrum. The MEMS sound transducer is preferably driven electromechanically, electrostatically, and/or piezoelectrically. An ASIC is an electronic application-specific integrated circuit (ASIC) suitable for operating the MEMS sound transducer. The term "cavity" can be understood as a cavity that can intensify the sound pressure of the MEMS sound transducer. According to the present invention, the ASIC is embedded in a first substrate, while the first MEMS sound transducer is arranged on a second substrate. Thus, the first substrate with the embedded ASIC and the second substrate with the at least partially embedded MEMS sound transducer represent two separate, i.e., separately manufactured, components. The first and second substrates are connected to each other. Thus, they have a common connection region in which they directly abut against each other. The connection between the two substrates is preferably achieved by a material bond, wherein the substrates are preferably adhesively bonded. Additionally or alternatively, the connection can also be produced by means of a positive fit and/or a non-positive fit. The two substrates are connected to one another in such a way that the ASIC and the first MEMS sound transducer are electrically conductively coupled or connected to one another.

A certain amount of scrap is unavoidable during the production of sound transducer assemblies. The sound transducer assembly according to the present invention can reduce the additional costs associated with scrap by first producing the substrates separately from one another. The functional effectiveness of at least one of their electronic components, namely the ASIC or MEMS sound transducer, is then tested. Only when their functional effectiveness is positive—that is, when it is ensured that the ASIC and/or MEMS sound transducer has not been damaged during the respective placement or embedding process—are they connected to one another, in particular, glued together. This ensures that only two functional substrates are connected to form a sound transducer assembly.

Furthermore, a method for producing such a sound converter assembly is proposed, which according to the invention comprises the steps of:

- arranging or embedding the ASIC in a first substrate,

- arranging the MEMS sound transducer on a second substrate,

- The first substrate and the second substrate are electrically conductively connected to each other.

The proposed sound transducer assembly and the proposed method offer numerous advantages for production. If the ASIC is completely embedded in the first substrate and/or the first cavity is at least partially formed in the first and/or second substrate, the sound transducer assembly can be designed to be very space-saving.

Due to the modular construction with at least two separate substrates, wherein the first substrate contains the ASIC and the second substrate carries the MEMS sound transducer, the sound transducer assembly can be produced much more efficiently.

Individual modules, which either comprise a first substrate and an ASIC (hereinafter referred to as an ASIC module) or a second substrate and a MEMS sound transducer (hereinafter referred to as a MEMS module), can be produced, tested, and, if necessary, temporarily stored independently of one another in separate subprograms. Each subprogram can be individually optimized.

The connection of the ASIC module and the MEMS module can be performed at a later stage in the manufacturing process. This connection can be achieved, in particular, by soldering, a conductive adhesive, and/or in another manner, so that the first and second substrates are connected to each other at least electrically conductively and preferably also in a form-fitting, force-fitting, and/or material-fitting manner.

Due to the possibility of producing individual modules individually, ASIC and/or MEMS modules can be manufactured in different variants and then combined to form a wide range of different sound transducer assemblies, for example by combining different MEMS module variants with one ASIC module variant, or combining one MEMS module variant with different ASIC module variants. This allows for a broad product range of freely configurable, diverse sound transducer assemblies while simultaneously exploiting economies of scale.

The ability to test each module individually allows for targeted and timely identification and isolation of defective modules. This allows only two faulty modules to be assembled into a sound converter assembly, while only the individual defective modules must be discarded. This reduces scrap, conserves valuable resources, protects the environment, and reduces costs. Furthermore, the connection between the two modules, or between the first and second substrates, is preferably detachable, so that, in subsequent repairs, only the defective module must be replaced with a new one.

Advantageously, the first cavity is formed at least partially in the first and/or second substrate, thereby making it possible to achieve a particularly large volume of the cavity.

In an advantageous embodiment of the present invention, a second MEMS sound transducer is arranged on a third substrate. The first and third substrates are electrically conductively connected to one another. Furthermore, such a sound transducer assembly includes a first substrate having an ASIC, a second substrate having the first MEMS sound transducer, and a third substrate having the second MEMS sound transducer. Preferably, the first substrate is arranged between the second and third substrates. Preferably, the second MEMS sound transducer also includes a cavity, wherein the second cavity is at least partially formed within the first and/or third substrates.

The modular design of the sound transducer assembly advantageously enables the connection of the ASIC module to another MEMS module comprising a third substrate and a second MEMS sound transducer. This connection can also be achieved, in particular, by welding, a conductive adhesive, and/or in another manner, so that the first and second substrates are connected to each other at least electrically conductively and preferably also in a form-fitting, force-fitting, and/or material-locking manner.

It will be appreciated that the features and advantages mentioned above with respect to the ASIC module and the MEMS module are essentially also applicable with respect to other MEMS modules.

In a sound transducer assembly having two MEMS modules, the two MEMS modules can be constructed with essentially the same or different representative features. In both cases, a sound transducer assembly configured with two MEMS modules generally has better efficiency than a sound transducer assembly configured with only one MEMS module, in particular in the form of a greater frequency bandwidth and/or a greater sound pressure.

According to a preferred embodiment, the two cavities of the MEMS sound transducer are separated from one another by a partition wall of the first substrate, wherein the two cavities thus do not influence one another. Preferably, the partition wall has at least one connecting hole extending from the first cavity to the second cavity, so that a flow connection exists between the two cavities and the volume of each cavity is increased by the volume of the respective other cavity. This allows the sound transducer assembly to be designed with a relatively large acoustically effective cavity volume in a very space-saving manner.

It is advantageous if the intermediate wall has at least one reinforcing element, in particular in the form of a rib, in order to achieve stability of the intermediate wall and thereby prevent deformations and/or resonances of the intermediate wall, or at least to significantly reduce them.

Preferably, the two cavities have volumes of different sizes. Thus, the cavity volume can be a representative feature that distinguishes the MEMS modules.

Advantageously, balancing holes and/or pressure-balancing air channels are formed in at least one base layer. These balancing holes and/or pressure-balancing air channels connect at least one cavity to the surrounding environment, thereby enabling pressure balancing. Such pressure-balancing holes have the advantage of being able to balance air pressure within a specific frequency range, thereby improving acoustic efficiency and quality.

Advantageously, at least one substrate, preferably all substrates, are designed as a circuit board or printed circuit board and/or are produced using printed circuit board technology.

In a preferred embodiment of the present invention, at least one cavity is at least partially filled with a porous material. This effectively increases the surface area inside the cavity and virtually expands the cavity volume, thereby enabling greater sound pressure and better bass playback. The porous material can be a single piece or multiple pieces and have one or more specific pore sizes. Thus, the characteristics of the porous material can also be a representative feature that distinguishes the MEMS module. Since the cavity is preferably still open and accessible until the first and second substrates are connected, the porous material can be easily inserted, even if it is present in one piece.

According to a preferred embodiment, the sound converter assembly comprises a housing part. This housing part provides protection, in particular, for the sensitive MEMS sound converter. Preferably, the housing part comprises at least one acoustic inlet/exit opening, which is preferably arranged laterally on the outside of the sound converter assembly. Preferably, the housing part is connected to at least one substrate in such a way that at least one sound duct is at least partially formed between the housing part and at least one substrate layer. With the aid of this sound duct, the sound produced by the MEMS sound converter acting as a MEMS loudspeaker can be advantageously intensified and/or directed in a targeted manner in the direction of the acoustic exit opening, or the sound entering and to be captured at the acoustic inlet opening can be intensified and/or directed in a targeted manner in the direction of the MEMS sound converter acting as a MEMS microphone. Due to the sound duct, the acoustic inlet/exit opening can be positioned essentially arbitrarily on the outside of the sound converter assembly, in particular with respect to the top side in the assembly orientation and/or with respect to the side.

Furthermore, the at least one sound duct preferably comprises a first part, in particular formed between the housing element and the at least one base layer, and/or a second part, in particular formed partially or completely within the housing element. Advantageously, no additional components are required for forming the sound duct. Furthermore, the sound converter assembly can thereby be designed in a very space-saving manner. The second part is preferably arranged directly adjacent to the acoustic entry/exit opening and/or at least partially encompasses it.

In another preferred embodiment, the sound converter assembly has a sound guiding element, which preferably has at least one, in particular concave, sound guiding edge. The sound guiding element is preferably arranged between the housing part and at least one base layer, in particular in the transition area between the first and second parts of the sound airway. The sound guiding element can be constructed separately or molded onto the housing part and/or the base layer. Advantageously, the sound guiding element and/or the sound guiding edge are constructed in such a way that the sound produced by the MEMS sound converter can be concentrated to the acoustic entry/exit opening, in particular in the direction of the second part of the sound airway, and/or the sound captured by the MEMS sound converter can be concentrated to the MEMS sound converter, in particular in the direction of the first part of the sound airway.

When the sound converter assembly comprises a first and a second MEMS sound converter, preferably each MEMS sound converter corresponds to a sound duct, which respectively provide a connection to the acoustic entry/exit hole. In particular, in order to save structural space, only one acoustic entry/exit hole can also be provided in the case where the sound converter assembly comprises two MEMS sound converters. The second part of the first sound duct and the second part of the second sound duct can then be constructed as a common part, at least in the area of the acoustic entry/exit hole. The sound guiding element can then preferably be constructed and arranged in such a way that it separates the first part of the first sound duct from the first part of the second sound duct. Particularly preferably, the sound guiding element has a protrusion, in particular extending from the first part into the second part.

In an advantageous embodiment of the invention, the first, second and/or third substrate is a printed circuit board substrate, that is to say a circuit board, which is constructed from one or preferably multiple layers, wherein the multiple layers are arranged one on top of the other in a sandwich-like manner and/or are connected to one another, preferably in a material-locking manner. In particular, the first substrate can have a recess for integrally accommodating the ASIC, which recess is configured, for example, as a circuit board cavity with a sufficiently large volume so that the ASIC can be arranged or embedded therein. In addition to the ASIC, other components, in particular inert components such as resistors, can also be embedded in the first substrate and/or arranged thereon. Preferably, the housing part and/or the sound guide element consists of a material that is different from the substrate, in particular a synthetic material and/or a metal.

Advantageously, the substrates are manufactured separately from one another. Here, the ASIC is embedded or encapsulated in the first substrate during its manufacture. The ASIC and/or additional active and/or inert electronic components are thus completely embedded in the first substrate. Furthermore, it is advantageous that the second substrate is manufactured separately from the MEMS sound transducer. Here, the MEMS sound transducer can, for example, be fixed to one side of the second substrate in a material-locking manner. Additionally or alternatively, the MEMS sound transducer can also be connected to the second substrate in a form-locking manner. For this purpose, for example, the frame of the MEMS sound transducer is surrounded by the second substrate in a form-locking manner. However, the diaphragm can vibrate freely. After each module—that is, the first module, in particular, comprising the ASIC and the first substrate, and/or the second module, comprising the MEMS sound transducer and the second substrate—has been manufactured in separate manufacturing steps, they are connected to one another, in particular by gluing, in a subsequent manufacturing step. This advantageously allows the functionality of the modules to be tested before final connection, thereby reducing scrap and, therefore, manufacturing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages of the present invention are described in the following embodiments.

FIG1 is a perspective sectional view of a first embodiment of a sound transducer assembly without a housing member,

FIG2 is a side sectional view of a first embodiment of the sound transducer assembly without the housing member,

FIG3 is a further side sectional view of the first embodiment of the sound transducer assembly without the housing member,

FIG4 is a perspective sectional view of a second embodiment of a sound transducer assembly having a housing member,

FIG5 is a side sectional view of a second embodiment of a sound transducer assembly having a housing member,

FIG6 is a further side cross-sectional view of a second embodiment of a sound transducer assembly having a housing member,

FIG7 is a perspective sectional view of a third embodiment of a sound transducer assembly having a housing member,

FIG8 is an exploded perspective view of a second embodiment of a sound transducer assembly,

FIG9 is a general perspective view of a third embodiment of a sound transducer assembly having a housing,

FIG10 is a side cross-sectional view of an acoustic transducer assembly having a housing and a cavity filled with a porous material,

FIG11 is a side cross-sectional view of a fifth embodiment of an acoustic transducer assembly having a housing and a cavity filled with a porous material,

FIG12 is a schematic side sectional view of a sixth embodiment of a sound transducer assembly without a housing,

FIG. 13 is a schematic side cross-sectional view of a seventh embodiment of a sound transducer assembly without a housing but having two MEMS sound transducers,

FIG. 14 is a side cross-sectional view of an eighth embodiment of an acoustic transducer assembly having a housing and two MEMS acoustic transducers,

FIG15 is a perspective cross-sectional view of a ninth embodiment of a sound transducer assembly without a housing member,

FIG16 is a side sectional view of a ninth embodiment of a sound transducer assembly without a housing member,

FIG17 is another side sectional view of the ninth embodiment of the sound transducer assembly without the housing member,

FIG. 18 is a perspective cross-sectional view of a tenth embodiment of a sound transducer assembly having a housing member,

FIG. 19 is a side sectional view of a tenth embodiment of an acoustic transducer assembly having a housing member,

FIG. 20 is another side sectional view of the tenth embodiment of the sound transducer assembly without the housing member,

FIG. 21 is a perspective cross-sectional view of an eleventh embodiment of a sound transducer assembly without a housing member,

FIG22 is a side sectional view of an eleventh embodiment of a sound transducer assembly without a housing member,

FIG23 is another side cross-sectional view of the eleventh embodiment of the sound transducer assembly without the housing member,

FIG. 24 is a perspective cross-sectional view of a twelfth embodiment of an acoustic transducer assembly having a housing member,

FIG. 25 is a side cross-sectional view of a twelfth embodiment of an acoustic transducer assembly having a housing member,

Figure 26 is another side cross-sectional view of the twelfth embodiment of the sound transducer assembly without the housing.

In the following descriptions of the figures, to define the relationships between various elements, the terms "above," "below," "up," "below," "above," "below," "to the left," "to the right," "vertical," and "horizontal" are used with reference to the positions of the various objects shown in the figures. It is understood that these terms may change if the positions of the devices and/or elements shown in the figures are offset. Thus, for example, if the orientation of the devices and/or elements is reversed relative to the figures, a feature specified as "above" in the following descriptions of the figures would now be arranged "below." Therefore, the relative terms used are merely used to more simply describe the relative relationships between the various devices and/or elements described below.

DETAILED DESCRIPTION

Figures 1 to 3 show various views of a first embodiment of a sound transducer assembly 1. Sound transducer assembly 1 essentially comprises a first substrate 10 configured as a circuit board and having an ASIC 11, and a second substrate 20 configured as a circuit board and having a MEMS sound transducer 21. The MEMS sound transducer 21 is connected to the ASIC 11 via electrical contacts (not shown in further detail in this figure). This allows the MEMS sound transducer 21 to be controlled or operated via the ASIC 11. Sound transducer assembly 1 has a substantially rectangular basic shape. This rectangular basic shape enables the sound transducer assembly to be manufactured simply and cost-effectively and is suitable for a wide range of applications. Alternatively, however, the sound transducer assembly can also have another basic shape, particularly a circular one.

MEMS sound transducer 21 is designed to generate and/or capture sound waves within the audible wavelength spectrum. To this end, in addition to MEMS actuator 22, MEMS sound transducer 21 includes further, particularly acoustic, components: a diaphragm 23, a diaphragm plate 24, and a diaphragm frame 25. Diaphragm 23, which is made of rubber, for example, is fixedly connected to diaphragm frame 25 in its edge regions and to diaphragm plate 24 in its center region, with diaphragm plate 24 itself not being connected to diaphragm frame 25. As a result, diaphragm 23 is tensioned against diaphragm frame 25 and supported by diaphragm plate 24 in its center region. If MEMS sound transducer 21 is to function as a loudspeaker, for example, it can be driven by ASIC 11 such that diaphragm 23 is set into oscillation relative to diaphragm frame 25 by MEMS actuator 22 to generate sound energy.

Second substrate 20 carries a MEMS actuator 22 and a diaphragm frame 25 with a diaphragm 23 fixed thereto. MEMS actuator 22 is arranged below diaphragm 23. Second substrate 20 has a cavity 29 below diaphragm 23 and MEMS actuator 22. Cavity 29 is laterally surrounded or bounded by walls 27 of second substrate 20 and closed at the top by diaphragm 23. Cavity 29 is bounded downward by first substrate 10, to which second substrate 20 is connected. Cavity 29 thus forms a cavity 41 of MEMS sound transducer 21, which serves, in particular, to increase the sound pressure of MEMS sound transducer 21.

As can be seen from Figures 1 to 3 , membrane frame 25 essentially has the same outer diameter as second substrate 20 , while MEMS actuator 22 has a smaller outer diameter than substrate 20 . As can be seen from a comparison of Figures 1 and 2 with Figure 3 , substantially opposite wall portions 27 a of second substrate 20 are thicker than wall portion 27 b of second substrate 20 , with thicker wall portion 27 a protruding further into cavity 29 than wall portion 27 b . MEMS actuator 22 rests only on protrusion 28 formed by wall portion 27 a , while membrane frame 25 rests not only on wall portion 27 a but also, in particular, over its entire surface, on wall portion 27 b . Thus, MEMS actuator 22 is laterally surrounded by membrane frame 25 .

The MEMS sound transducer 21 and in particular the MEMS actuator 22 and/or the diaphragm frame 25 can be adhesively bonded to the second substrate 20. Furthermore, the second substrate 20 can be adhesively bonded to the first substrate 10.

To ensure pressure balance between cavity 41 and the surrounding environment during oscillation of diaphragm 23, sound converter assembly 1 includes at least one pressure-balancing air channel 70, which in this embodiment includes balancing holes 26 and is preferably arranged not in the thick wall portion 27 of second substrate 20 but in the thin wall portion 27. Thus, when diaphragm 23 is lowered, air can flow out of cavity 41, formed by cavity 29, through pressure-balancing air channel 70 for pressure balance. Similarly, when diaphragm 23 is raised, air can flow into cavity 41 through pressure-balancing air channel 70.

First substrate 10 has a cavity 13a, which is substantially completely enclosed. ASIC 11 is arranged within cavity 13a. Thus, ASIC 11 is completely embedded within first substrate 10. In addition to ASIC 11, sound converter assembly 1 also has electrically conductive, particularly inert, accessories 12a, 12b, such as resistors and/or input/output contacts. Accessories 12a, 12b are also embedded within first substrate 10, being arranged within another cavity 13b of substrate 10, which is also substantially completely enclosed. Alternatively, electronic accessories 12a, 12b can also be arranged within cavity 13a together with ASIC 11.

Figures 4 to 26 illustrate further embodiments of the sound converter assembly 1, wherein the differences with respect to the first embodiment described above are essentially discussed. Therefore, in the following description of the further embodiments, the same reference numerals are used for the same symbols. Unless otherwise explained in detail, the design and function correspond to those described above. The differences described below can be combined with the above and following embodiments.

Figures 4 to 6 show various views of a second embodiment of a sound transducer assembly 1. Unlike the first embodiment, the second embodiment of the sound transducer assembly 1 additionally includes a housing element 50. Housing element 50 provides protection, in particular, for the MEMS sound transducer 21. Housing element 50 has a cavity 53 within which the second substrate 20 and the MEMS sound transducer 21 are substantially completely accommodated. This cavity is closed downwardly by the first substrate 10, to which the housing element 50 is connected.

Furthermore, housing element 50 has an acoustic inlet/exit opening 51, which is arranged laterally thereto and simultaneously on the outer surface 55 of the sound transducer assembly. Furthermore, housing element 50 is connected to first substrate 10 and, in particular, is dimensioned such that at least a first portion 62 of a sound channel 61 is formed between housing element 50 and second substrate 20 having MEMS sound transducer 21. A second portion 63 of sound channel 61 is itself formed within housing element 50. Furthermore, housing element 50 has a tubular extension 52 in the region of acoustic inlet/exit opening 51. Consequently, no additional components are required to form sound channel 61. In other words, sound channel 61 is at least partially formed by not completely filling cavity 53 of housing element 50 with second substrate 20 and MEMS sound transducer 21.

Sound can be guided from MEMS sound transducer 21 to acoustic inlet/exit opening 51 and/or vice versa and/or amplified by means of sound duct 61. Due to sound duct 61, acoustic inlet/exit opening 51 can be positioned essentially arbitrarily on outer surface 55 or another outer surface of sound transducer assembly 1, in particular on the top side and/or on the side relative to the mounting orientation.

Housing part 50 also has an acoustic balancing hole 56, which is arranged laterally on outer surface 58 of housing part 50. Here, balancing hole 56 corresponds to balancing hole 26 and, like balancing hole 26, belongs to pressure balancing passage 70 of sound converter assembly 1. In this example, balancing hole 56 has a larger diameter than balancing hole 26. To prevent dirt and/or liquid from entering cavity 41 through pressure balancing passage 70, balancing hole 56 in this example is covered by an elastic closure element 57. The pressure balancing function is still ensured because elastic closure element 57 can be deformed by the pressure prevailing in cavity 41.

7 to 9 show different views of a third embodiment of the sound converter assembly 1. The essential difference with respect to the first and second embodiments is that in the third embodiment the cavity 41 is partially formed by the cavity of the first and second substrates 10, 20, respectively.

As can be seen in particular from Figures 7 and 8, the membrane frame 25 essentially has the same outer diameter as the MEMS actuator 22, wherein this outer diameter is smaller than the outer diameter of the second substrate 20. However, the walls 27 of the second substrate 20, which laterally delimit a cavity 29 of the second substrate, each have, in their upper region, wall portions 27b protruding into the cavity 29 and providing a preferably full-surface support 28 for the MEMS actuator 22, wherein the membrane frame 25 also rests on the outer region of the MEMS actuator 22. Thus, in this example, the second substrate 20 also carries the MEMS actuator 22 and the membrane frame 25 with the diaphragm 23 fixed thereto, wherein the MEMS actuator 22 is arranged below the diaphragm 23, wherein the second substrate 20 has a cavity 29 below the diaphragm 23 and the MEMS actuator 22, which is closed at the top by the diaphragm 23.

Cavity 29 of second substrate 20 is open at the bottom and adjoins cavity 15 of first substrate 10, which is open at the top. Cavity 15 is laterally bounded by walls 16 of the first substrate and closed at the bottom by first substrate 10. Cavities 15 and 29 have equal diameters, and the lower free end of wall 27 corresponds to the upper free end of wall 16. When sound transducer assembly 1 is assembled, wall 16 of first substrate 10 is connected to wall 27 of second substrate 20, and in particular, is adhesively bonded. Cavity 15 of the first substrate and cavity 29 of the second substrate are arranged one above the other and then together form cavity 41 of MEMS sound transducer 21.

The pressure equalization air passage 70 is not shown in the figure in this example, but may be preferably provided.

In this example, housing part 50 is of very economical design and, apart from an outer surface 55 , on which the acoustic inlet/exit opening 51 with the tubular projection 52 is arranged, has essentially only a further outer surface 54 , which in particular provides protection for MEMS sound transducer 21 .

However, the housing part 50 is connected to the first substrate 10 and the second substrate 20 in such a way that at least a first portion 62 of the sound channel 61 is formed between the housing part 50 and the second substrate 20 having the MEMS sound transducer 21 and the first substrate 10. In this example, the second portion 63 of the sound channel 61 is also itself located within the housing part 50 and is formed, in particular, by the tubular projection 52.

To further improve sound guidance and, in particular, to concentrate the sound, a sound guiding element 64 with a concave sound guiding edge 65 is provided in this example. This element is arranged between the housing 50 and the first and second substrates within the sound channel 61. More precisely, the sound guiding element 64 is arranged in the transition area between the first and second parts 62, 63 of the sound channel 61. The sound guiding element is designed as a single component. Alternatively, it can be molded into the housing 50 and/or onto the substrate.

Sound guide element 64 can be seen particularly well in Figures 8 and 9. Figure 8 shows an exploded view of a sound transducer assembly 1 according to a third exemplary embodiment. This allows a good view of not only sound guide element 64 with its concave sound guide edge 65, but also other components of sound transducer assembly 1, such as ASIC 11, substrates 10 and 20, primary MEMS actuator 22, diaphragm 23 on diaphragm frame 25, and diaphragm plate 24. Figure 9 shows housing part 50 in a semi-transparent manner, so that the protected rearward components of sound transducer assembly 1 can also be clearly seen.

10 shows a fourth embodiment of the sound converter assembly 1 . In contrast to the third embodiment, in the fourth embodiment of the sound converter assembly 1 the cavity 41 is at least almost completely filled with the porous material 5 .

FIG11 shows a fifth embodiment of an acoustic transducer assembly 1. Unlike the second embodiment, in the fifth embodiment of the acoustic transducer assembly 1, the cavity 41 is at least nearly completely filled with the porous material 5. Filling the cavity 41 of the MEMS acoustic transducer 21 effectively increases the surface area within the cavity and virtually increases the cavity volume, thereby achieving greater sound pressure and improved bass reproduction.

FIG12 shows a sixth exemplary embodiment of a sound transducer assembly 1. This is a purely schematic illustration of a sound transducer assembly 1 comprising a first substrate 10 with an ASIC 11 and a second substrate 20 with a MEMS sound transducer 21, but without a housing. Only the MEMS actuator 22 of the MEMS sound transducer 21 is shown.

Both the first substrate 10 and the second substrate 20 have conductor tracks 7 for electrically conductively connecting individual components, such as, in particular, the ASIC 11 and the MEMS actuator 21. The conductor tracks 7 of the first substrate 10 are connected to the conductor tracks 7 of the second substrate 20 by means of soldering 8 or an electrically conductive adhesive 8. In addition to this electrically conductive connection 8, the two substrates 10, 20 can also be connected to each other in other ways, such as in a form-fitting, force-fitting, and/or material-locking manner.

Second substrate 20 has a cavity 29, which is laterally enclosed or bounded by walls 27 of second substrate 20 and closed downwardly by first substrate 10. Wall 27 has a wall portion 27a protruding into cavity 29 and providing support 28 for MEMS actuator 22, which has a smaller outer diameter than second substrate 20. Cavity 29 is closed upwardly by further acoustic components of the MEMS sound transducer, which are associated with MEMS actuator 22 but are not shown here. Cavity 29 thus forms a cavity 41 of the MEMS sound transducer.

FIG13 shows a seventh exemplary embodiment of a sound transducer assembly 1. This is again a purely schematic illustration of a sound transducer assembly 1. Unlike the sixth exemplary embodiment, the sound transducer assembly 1 of this seventh exemplary embodiment additionally includes a third substrate 30 having a second MEMS sound transducer, of which only the MEMS actuator 32 is shown here.

Here, first substrate 10 is arranged between second substrate 20 and third substrate 30. Third substrate 30 with second MEMS actuator 32 is essentially designed like second substrate 20 with first MEMS actuator 22, but is arranged 180° rotated relative to second substrate 20.

The third substrate 30 also has conductor tracks 7 for electrically conductively connecting the individual components. The conductor tracks 7 of the third substrate 30 are likewise connected to the conductor tracks 7 of the first substrate by means of soldering 8 or an electrically conductive adhesive 8. In addition to the electrically conductive connection 8, the two substrates 10, 30 can also be connected to each other in other ways in a form-fitting, force-fitting, and/or material-locking manner.

Third substrate 30 has a cavity 39, which is laterally surrounded or bounded by walls 37 of third substrate 30 and closed off at the top by first substrate 10. Cavity 39 is closed off at the bottom by further acoustic components of second MEMS sound transducer 31, which are associated with second MEMS actuator 32 but are not shown here. Cavity 39 thus forms a second cavity 42 of the second MEMS sound transducer.

In the seventh embodiment of the sound converter assembly 1, first and second cavities 41 and 42, while separate, are essentially constructed with the same typical features, such as size and volume. Here, the two cavities 41 and 42 are separated by a partition 17, which is provided by the first substrate 10, so that the two cavities 41 and 42 do not interfere with each other. Optionally, the partition 17 may also include at least one connecting hole extending from the first cavity 41 to the second cavity 42, although this is not shown here. This connecting hole thus enables a flow connection between the two cavities, thereby allowing the volume of one cavity to be increased by the volume of the other cavity.

14 shows an eighth embodiment of a sound transducer assembly 1 . Different from the third embodiment, the sound transducer assembly 1 of the eighth embodiment additionally includes a third substrate 30 having a second MEMS sound transducer 31 .

Here, first substrate 10 is arranged between second substrate 20 and third substrate 30. Third substrate 30 with second MEMS actuator 31 is constructed essentially like second substrate 20 with first MEMS actuator 21, but is arranged 180° rotated relative to second substrate 20.

Similar to cavity 15 on its upper side, first substrate 1 has cavity 18 on its lower side, which is laterally bounded by walls 19 of the first substrate and closed upward by first substrate 10. Cavity 18 is open downward and adjoins an upwardly open cavity 39 of third substrate 30. Cavity 39 is laterally surrounded or bounded by walls 37 of third substrate 30 and closed downward by diaphragm 33 of second MEMS sound transducer 31. Cavities 18 and 39 have equal diameters, with the lower free end of wall 19 corresponding to the upper free end of wall 37. When sound transducer assembly 1 is assembled, wall 19 of first substrate 10 is connected to wall 37 of third substrate 30, and in particular, is adhesively bonded. Cavity 18 of the first substrate and cavity 39 of the third substrate are arranged one above the other and then together form cavity 42 of MEMS sound transducer 31.

In contrast to the seventh embodiment, the first and second cavities 41, 42 in this eighth embodiment have different typical features and, in particular, different dimensions and different cavity volumes. This is essentially caused solely by the fact that the top wall 16 of the first substrate 10 is higher than the bottom wall 19 of the first substrate 10.

Due to the differently designed cavities 41, 42, different tonal characteristics can be detected from first and second MEMS sound transducers 21, 31, even under otherwise identical conditions. Alternatively or additionally, the tonal characteristics of both MEMS sound transducers can be specifically influenced by specifically designing diaphragms 23, 33 and/or MEMS actuators 22, 32. Thus, for example, one MEMS sound transducer can function as a woofer while the other functions as a tweeter. Thus, a sound transducer assembly configured in this manner can produce sound over a wider frequency bandwidth than, for example, the sound transducer assembly according to the third embodiment.

Partition 17, provided by first substrate 10 and separating two cavities 41, 42 from one another, has four reinforcing elements 14, which are rib-shaped and serve to stabilize partition 17. This significantly reduces or even prevents deformation and/or resonance of partition 17, particularly during operation of sound converter assembly 1. According to this embodiment, partition 17 has at least one connecting hole 90. Connecting hole 90 connects two cavities 41, 42 to one another.

In this case, the housing part 50 is constructed very economically similar to the third embodiment and, apart from an outer surface 55 on which the acoustic entry/exit opening 51 with a tubular protrusion 52 is arranged, basically only has further outer surfaces 54a and 54b, which provide protection in particular for the first MEMS sound transducer 21 and the second MEMS sound transducer 31.

However, housing part 50 is also connected to first substrate 10, second substrate 20, and third substrate 30 in such a way that first and second sound channels 61, 67 are formed. Here, at least one first portion 62 of first sound channel 61 is formed between housing part 50 and second substrate 20, which in particular has MEMS sound transducer 21, and at least one first portion 68 of second sound channel 67 is formed between housing part 50 and third substrate 30, which in particular has MEMS sound transducer 31.

In particular, in order to save structural space, only one acoustic inlet/exit opening 51 is provided in this sound converter assembly 1. Thus, the second portion 63 of the first sound duct 61 and the second portion 69 of the second sound duct 67 are constructed as a common part, which in this case is also constructed in the housing part 50 itself and in particular by a tubular extension 52 in the area of the acoustic inlet/exit opening 51.

To further improve the sound guidance and, in particular, to concentrate the sound, a sound guidance element 64 is also provided in this example. Here, the sound guidance element 64 is designed and arranged so that it separates the first portion 62 of the first sound duct 61 from the first portion 68 of the second sound duct 67. To this end, the sound guidance element 64 has a projection 66 that projects into the common second portion. Furthermore, the sound guidance element 64 in this example has two concave sound guidance edges 65a and 65b, with the sound guidance edge 65a corresponding to the first sound duct 61 and the sound guidance edge 65b corresponding to the second sound duct 67.

15 to 17 show views of a ninth embodiment of the sound converter assembly 1. In contrast to the first embodiment, an additional substrate 80 is provided in the ninth embodiment of the sound converter assembly 1.

In the exemplary embodiment shown here, the membrane frame 25 also has essentially the same outer diameter as the second substrate 20, while the MEMS actuator 22 has a smaller outer diameter than the substrate 20. However, the wall 27 of the second substrate 20, which laterally delimits the cavity 29 of the second substrate 20, does not have any wall portion protruding into the cavity 29, which could serve as a support for the MEMS actuator 22. As a result, the additional substrate 80 rests on the wall 27 of the second substrate 20 and, in particular, has essentially the same outer diameter as the second substrate 20 over its entire surface.

Additional substrate 80 has a cavity 89, which is laterally bounded by walls 87 of substrate 80, wherein walls 87 have a significantly smaller height than walls 27 of second substrate 20. Substantially opposite wall portions 87a of substrate 80 are thicker than wall portions 87b of substrate 80, with thicker wall portions 87a protruding relative to wall portions 87b into cavity 89. MEMS actuator 22 then rests on protrusion 88 formed by wall portion 87a, while diaphragm frame 25 rests on wall portions 87a and 87b, in particular, over its entire surface. MEMS actuator 22 is thus arranged below diaphragm 23 and laterally surrounded by diaphragm frame 25.

As a result, cavity 89 is closed upward by diaphragm 23. Cavity 89 is open downward and adjoins the upwardly open cavity 29 of second substrate 20, which is closed downward by first substrate 10. The superimposed cavities 29 and 89 thus together form cavity 41 of MEMS sound transducer 21. Since wall 27 of second substrate 20 does not have any wall portion protruding into cavity 29, such wall portion would reduce cavity 29, thereby contributing to the expansion of cavity 41 formed jointly by cavity 29.

18 to 20 show various views of a tenth exemplary embodiment of a sound converter assembly 1. Unlike the ninth exemplary embodiment, the tenth exemplary embodiment of the sound converter assembly 1 further comprises a housing element 50 that is constructed essentially as in the second exemplary embodiment. In contrast to the second exemplary embodiment, in the tenth exemplary embodiment of the sound converter assembly 1, an additional substrate 80 is also accommodated in the cavity 53 of the housing element 50.

21 to 23 show various views of an eleventh embodiment of the acoustic transducer assembly 1. Unlike the first embodiment, in the eleventh embodiment of the acoustic transducer assembly 1, the second substrate 20, the MEMS actuator 22, and the diaphragm frame 25 of the first MEMS acoustic transducer 21 have the same outer diameters.

Walls 27 of second substrate 20, which laterally delimit cavity 29 of second substrate 20, do not have any wall sections protruding into cavity 29 and which would be necessary for supporting MEMS actuator 22. Instead, MEMS actuator 22 preferably rests entirely on wall 27 of second substrate 20, with membrane frame 25 also resting on the outer edge regions of MEMS actuator 22.

Thus, in this example, the second substrate 20 also carries a MEMS actuator 22 and a membrane frame 25 having a membrane 23 fixed thereon, wherein the MEMS actuator 22 is arranged below the membrane 23, and the second substrate 20 has a cavity 29 below the membrane 23 and the MEMS actuator 22, which is closed at the top by the membrane 23.

The cavity 29 of the second substrate 20 is closed at the bottom by the first substrate 10 .

In this exemplary embodiment, cavity 41 of MEMS sound transducer 21 formed by cavity 29 can also be enlarged effectively and at the same time in a very space-saving manner.

24 to 26 show different views of a twelfth exemplary embodiment of a sound converter assembly 1. In contrast to the eleventh exemplary embodiment, in the twelfth exemplary embodiment of the sound converter assembly 1, a housing part 50 is additionally provided, which is constructed essentially as in the second exemplary embodiment.

The invention is not limited to the exemplary embodiments shown and described. Variations such as feature combinations are also possible within the scope of the claims, even if they are shown and described in various exemplary embodiments.

Reference Signs List

89 cavity

90 connection hole

70 Pressure Balance Airway

80 additional base

87a, b wall, wall portion

88 protrusion, support

89 cavity

90 connection hole

70 Pressure Balance Airway

80 additional base

87a, b wall, wall portion

88 protrusion, support

89 cavity

90 connection hole

70 Pressure Balance Airway

80 additional base

87a, b wall, wall portion

88 protrusion, support

89 cavity

90 connection hole

70 Pressure Balance Airway

80 additional base

87a, b wall, wall portion

88 protrusion, support

89 cavity

90 connection hole

70 Pressure Balance Airway

80 additional base

87a, b wall, wall portion

88 protrusion, support

Claims (14)

1. A sound converter assembly (1) having a first MEMS sound converter (21) for generating or acquiring sound waves in the audible wavelength spectrum, the first MEMS sound converter including a first hole (41) and having The ASIC (11) is electrically connected to the first MEMS sound converter. Its features are, The ASIC (11) is embedded in the first base layer (10). The first MEMS sound converter (21) is arranged inside or on the second base layer (20). The first cavity (41) is at least partially constructed in the first base layer (10) and/or the second base layer (20); The first substrate (10) and the second substrate (20) are interconnected, so that the ASIC (11) and the first MEMS sound converter (21) are electrically coupled to each other; A second MEMS sound converter (31) is arranged on the third base layer (30). The first base layer (10) and the third base layer (30) are electrically connected to each other. The first base layer (10) is arranged between the second base layer (20) and the third base layer (30), and The second cavity (42) of the second MEMS sound converter (31) is at least partially constructed within the first substrate (10) and/or the third substrate (30), and The two cavities (41, 42) are separated from each other by the partition wall (17) of the first base layer (10). 2. The sound converter assembly according to claim 1, characterized in that, Adjacent substrates are welded together or bonded together using conductive adhesive. 3. The sound converter assembly according to claim 1, characterized in that, The partition wall (17) has at least one connecting hole (90) extending from the first cavity (41) to the second cavity (42). 4. The sound converter assembly according to claim 1, wherein the partition (17) has at least one reinforcing element (14). 5. The sound converter assembly according to claim 1, characterized in that a balance hole (26) and/or a pressure balance airway (70) are constructed in the second base layer (20), which allows the first cavity (41) to communicate with the surrounding environment. 6. The sound converter assembly according to claim 1, wherein at least one cavity is at least partially filled with a porous material (5). 7. The sound converter assembly according to claim 1, characterized in that, The sound converter assembly (1) has a housing (50) having an acoustic inlet/outlet port (51) disposed on the outside (55) of the sound converter assembly (1), and/or The housing is connected to the first base layer (10), the second base layer (20) and the third base layer (30) such that a first acoustic airway (61) and a second acoustic airway (67) are formed at least partially between the housing (50) and at least one base layer. 8. The sound converter assembly according to claim 7, characterized in that, The first acoustic airway (61) has a first portion (62) constructed between the housing (50) and the second base layer (20) or a second portion (63) constructed entirely within the housing (50); The second acoustic airway (67) has a first portion (68) constructed between the housing (50) and the third base layer (30) or a second portion (69) constructed entirely within the housing (50). 9. The sound converter assembly according to claim 7, characterized in that, The sound converter assembly (1) has a sound guiding element (64) having at least one concave sound guiding edge (65) disposed between the housing (50) and the first base layer (10) and the second base layer (20), in the transition region between the first portion (62) and the second portion (63) of the first sound air passage (61). 10. The voice converter assembly according to claim 9, characterized in that, The sound guiding element (64) and/or the sound guiding edge (65) are configured such that the sound generated by the MEMS sound converter (21, 31) can be concentrated in the direction of the second part of the sound air passage to the acoustic inlet/outlet port (51). and/or The sound that is about to be acquired by the MEMS sound converter (21, 31) is concentrated in the direction of the first part of the sound airway to the MEMS sound converter. 11. The sound converter assembly according to claim 9, characterized in that, The sound guiding element (64) separates the first portion (62) of the first sound airway (61) from the first portion (68) of the second sound airway (67). 12. The sound converter assembly according to claim 9, characterized in that, The sound guiding element (64) has a protrusion (66) extending from the first part into the second part. 13. The voice converter assembly according to claim 9, characterized in that, At least one of the first substrate (10), the second substrate (20), and the third substrate (30) is a printed circuit board substrate, and/or The housing (50) and/or the sound guiding element (64) are made of a composite material and/or metal that are different from the base layer. 14. A method for manufacturing a sound converter component as described in any one of claims 1 to 13, comprising the following steps: - The ASIC (11) is arranged within the first base layer (10). - The first MEMS sound converter (21) is arranged inside or on the second base layer (20). - The second MEMS sound converter (31) is arranged on the third base layer (30). - Make the first base layer (10) and the second base layer (20) electrically connected to each other.