EP3135044B1 - Loud speaker arrangement with circuit-board-integrated asic - Google Patents

Description

The present invention relates to a loudspeaker arrangement comprising a printed circuit board, a MEMS loudspeaker for generating sound waves in the audible wavelength spectrum and an ASIC electrically connected to the MEMS loudspeaker.

The term MEMS stands for microelectromechanical systems. MEMS speakers or microspeakers, for example, from the DE 10 2012 220 819 A1 known. The sound is generated by a vibrating diaphragm of the MEMS loudspeaker. Such a microspeaker usually has to generate a high air volume shift in order to achieve a significant sound pressure level. Known MEMS speakers have the disadvantage that they have a relatively large volume of construction.

Object of the present invention is to provide a speaker assembly which is very compact.

The object is achieved by a loudspeaker arrangement having the features of independent patent claim 1.

A loudspeaker arrangement is proposed for MEMS loudspeakers which are suitable for generating sound waves in the audible wavelength spectrum. The loudspeaker arrangement comprises a printed circuit board, a MEMS loudspeaker and an ASIC. The MEMS loudspeaker is a microelectromechanical system for generating sound waves in the audible wavelength spectrum. The MEMS loudspeaker has a diaphragm which is deflectable in a z-axis of the MEMS loudspeaker. The MEMS loudspeaker is preferably electromechanically, electrostatically and / or piezoelectrically driven. The MEMS speaker is electrically connected to the ASIC connected. The circuit board has a substantially closed, first circuit board cavity. In this first circuit board cavity of the ASIC is arranged. The ASIC is thus completely integrated in the printed circuit board. As a result, the ASIC is protected against external influences inside the first printed circuit board cavity of the printed circuit board. The circuit board has a second circuit board cavity. The second circuit board cavity includes an opening. The MEMS speaker extends over the opening of the second circuit board cavity such that the opening is completely closed by it. Furthermore, the MEMS speaker extends over the opening such that the second circuit board cavity forms at least a portion of a cavity of the MEMS speaker. The term "cavity" is to be understood as a cavity by means of which the sound pressure of the MEMS loudspeaker can be amplified. If the ASIC is completely integrated in the printed circuit board and at the same time the circuit board at least partially forms the cavity of the MEMS loudspeaker, the loudspeaker arrangement can be made very compact. The loudspeaker arrangement has a sound-conducting channel. The sound transmission channel is arranged adjacent to the MEMS loudspeaker. The sound generated by the MEMS loudspeaker is thus dissipated via the sound conduction channel. At its end remote from the MEMS loudspeaker, the sound-conducting channel has an acoustic outlet opening. About this, the generated sound can leave the speaker assembly. The Schallleitkanal extends obliquely, in particular at 90 ° to the z-axis of the MEMS speaker. The acoustic exit opening is arranged on a side surface of the loudspeaker arrangement. The side surface is preferably aligned parallel to the z-axis and / or the surface normal of the side surface is preferably aligned perpendicular to the z-axis. It is advantageous if the printed circuit board has a third printed circuit board cavity in which the MEMS loudspeaker is at least partially arranged. As a result, the MEMS loudspeaker can be integrated in a form-fitting manner, at least partially, in the printed circuit board, whereby the overall volume of the Speaker arrangement reduced. Preferably, the third circuit board cavity to the second circuit board cavity, in particular immediately adjacent. Furthermore, the third printed circuit board cavity is preferably, in particular directly, formed in the region of the opening of the second printed circuit board cavity. The MEMS speaker is further fixed in particular form-fitting in the circuit board. In addition, the MEMS loudspeaker with the circuit board cohesively, in particular by gluing, and / or non-positively, in particular by pressing, be firmly connected to the circuit board.

In an advantageous development of the invention, the MEMS loudspeaker in the printed circuit board, preferably completely, integrated and / or embedded. This integration of the MEMS loudspeaker into the printed circuit board is preferably designed such that the third printed circuit board cavity engages around the MEMS loudspeaker in its edge region, preferably in the shape of a frame and / or in the region of its side facing and / or facing away from the second printed circuit board cavity. The MEMS loudspeaker can thus be integratively and firmly connected to it during the layered production of the printed circuit board. As a result, the manufacturing process of the speaker assembly can be made very simple and inexpensive.

In order to amplify the sound generated by the MEMS loudspeaker and / or to be able to direct it specifically in one direction or to one side of the loudspeaker arrangement, it is advantageous if the loudspeaker arrangement has a sound conduction channel adjacent to the third circuit board cavity, in particular directly. Preferably, the Schallleitkanal is at least partially formed by a fourth circuit board cavity of the circuit board. As a result, no additional components are advantageously necessary for the formation of the Schallleitkanals. Furthermore, the speaker assembly can thus be designed to save space.

In addition, it is furthermore advantageous if the sound-conducting channel has an acoustic outlet opening towards a side surface of the loudspeaker arrangement, in particular the printed circuit board. From this outlet opening, the sound generated by the MEMS loudspeaker can emerge from the loudspeaker arrangement, in particular the printed circuit board.

It is advantageous if the printed circuit board has a fourth printed circuit board cavity. This fourth printed circuit board cavity preferably forms at least partially the sound-conducting channel. As a result, the speaker assembly can be made very compact and inexpensive.

For securely fixing the MEMS loudspeaker in the printed circuit board, it is advantageous if the third printed circuit board cavity has a greater width than the second and / or fourth printed circuit board cavity for the positive engagement of the MEMS loudspeaker. In addition to this form-fitting fixation of the MEMS loudspeaker, it may optionally be fixed in the third printed circuit board cavity - which may also be formed as a printed circuit board recess on an outer surface of the printed circuit board - in a material-locking and / or non-positive manner.

It is advantageous if the width of the sound conduction channel, in particular of the fourth printed circuit board cavity, increases at least in regions, in particular in the direction of the outlet opening, in particular starting from the MEMS loudspeaker and / or third printed circuit board cavity. This increase in width is preferably funnel-shaped.

The MEMS loudspeaker preferably points to an outer surface, in particular to a built-in upper side of the loudspeaker arrangement and / or the printed circuit board. In order to be able to conduct the sound generated by the MEMS loudspeaker in a direction deviating from the orientation of the MEMS loudspeaker in accordance with the installation, it is advantageous if the sound conduction duct, in particular, the fourth circuit board cavity, a first region and a second region. The first area is preferably arranged adjacent to the MEMS loudspeaker. The second region is arranged in particular adjacent to the outlet opening. In order to be able to conduct the sound in a direction independent of the orientation of the MEMS loudspeaker, it is advantageous if the first and second regions are inclined relative to each other by an angle. For this purpose, the Schallleitkanal be bent and / or kinked. The angular inclination of the two areas is preferably 90 °. As a result, the MEMS loudspeaker can be oriented toward an upper or lower side of the loudspeaker arrangement, in particular the printed circuit board, whereby the generated sound can emerge in another area, in particular on a side surface of the printed circuit board.

A very compact design of the speaker assembly can be effected when the MEMS speaker is fully integrated in the circuit board and the circuit board at least partially forms the cavity and the Schallleitkanal. For this purpose, it is advantageous if the second and fourth printed circuit board cavities are spaced apart from one another by means of the third printed circuit board cavity. Furthermore, it is advantageous if the second and fourth printed circuit board cavities are separated from one another by means of the MEMS loudspeaker integrated in the third printed circuit board cavity.

In an advantageous development of the invention, the MEMS loudspeaker comprises a carrier substrate, a substrate cavity formed in the carrier substrate and a membrane. The carrier substrate preferably forms a frame here. For this purpose, the substrate cavity, in particular on two opposite sides of the carrier substrate, on a first and second substrate opening. The frame-shaped carrier substrate is therefore preferably open to an upper side and to a lower side of the MEMS loudspeaker. One of these two substrate openings, in particular the first substrate opening, is spanned in such a way by means of the membrane, which is preferably connected in its edge region to the carrier substrate, in that the membrane is able to vibrate relative to the carrier substrate in order to generate sound energy.

To form the largest possible cavity, it is advantageous if the MEMS loudspeaker is oriented relative to the printed circuit board in such a way that the substrate cavity and the second printed circuit board cavity together form the cavity of the MEMS loudspeaker. As a result, the volume of the cavity, which is formed at least by the second circuit board cavity, can be additionally increased by the volume of the substrate cavity. For this purpose, the second substrate opening of the MEMS loudspeaker is preferably oriented toward the second printed circuit board cavity.

It is also advantageous if the MEMS loudspeaker is oriented relative to the printed circuit board such that the substrate cavity, in particular together with the fourth printed circuit board cavity, at least partially forms the sound channel. As a result, the speaker assembly can be made very compact. In this regard, it is advantageous if the second substrate opening faces away from the second circuit board cavity.

The loudspeaker arrangement can be produced in a very simple and cost-effective manner if the printed circuit board is constructed in the form of a sandwich of a plurality of layers arranged one above the other and / or connected to one another, preferably cohesively.

For integrating the ASIC, the cavity, the MEMS loudspeaker and / or the sound conduction channel in the circuit board, it is advantageous if at least one of these layers has a first recess, by means of which at least partially the first printed circuit board cavity is formed for embedded recording of the ASIC. Additionally or alternatively, it is also advantageous if at least one of these layers has a second recess, by means of which at least partially the second, third and / or fourth printed circuit board cavity is formed.

Preferably, the circuit board comprises a plurality of layers arranged one above the other with such a first and / or second recess, so that the printed circuit board cavity formed by this has a correspondingly sufficient volume, in particular height, that the ASIC can be arranged therein. Furthermore, in this way a correspondingly sufficient volume of the respective printed circuit board cavity can be formed for receiving the MEMS loudspeaker.

It is advantageous if the second circuit board cavity together with the third and / or fourth circuit board cavity form a common acoustic cavity, which is subdivided into the cavity and at least part of the sound transmission channel by means of the MEMS loudspeaker.

In order to make the loudspeaker arrangement as flat as possible, it is advantageous if the first and second circuit board cavities, in particular the first and second recesses, are arranged next to one another. Furthermore, it is advantageous if the first and second printed circuit board cavities are separated from one another. To be able to form the loudspeaker arrangement as narrow as possible, it is alternatively also advantageous if the first and second circuit board cavities are arranged one above the other and / or, in particular by means of a layer, are separated from one another.

To generate sound waves, the membrane oscillates in the Z direction at least partially into the second and / or fourth printed circuit board cavity. For pressure compensation, it is advantageous if the printed circuit board has at least one pressure equalization channel. This connects the second circuit board cavity with an outer surface of the speaker assembly. The pressure equalization channel preferably extends from the second printed circuit board cavity up to an outer surface of the loudspeaker arrangement, in particular the printed circuit board. Furthermore, this preferably has on at least one of the outer surfaces of the speaker assembly, in particular the circuit board, preferably a side surface, a bottom and / or a top, a compensation opening.

It is advantageous if the pressure compensation channel has a first section, in particular connected to the second circuit board cavity, and a second section, in particular connected to the compensation opening, which are connected to one another and are preferably inclined relative to one another by an angle, in particular 90 °. Preferably, the two sections are connected to each other via a kink or a bend. Depending on the installation situation of the loudspeaker arrangement, the compensation opening can thus be arranged in an optimum region on one of the outer surfaces of the loudspeaker arrangement, in particular the printed circuit board.

Further proposed is a loudspeaker arrangement, which is preferably designed according to the preceding description, wherein said Merkamle may be present individually or in any combination. The loudspeaker arrangement comprises a printed circuit board, a MEMS loudspeaker for generating sound waves in the audible wavelength spectrum and an ASIC electrically connected to the MEMS loudspeaker. The printed circuit board has a first printed circuit board cavity in which the ASIC is arranged, so that it is completely integrated in the printed circuit board. The circuit board has a second circuit board cavity with an opening closed by the MEMS loudspeaker. The second circuit board cavity thus forms at least part of a cavity of the MEMS loudspeaker. The printed circuit board has at least one pressure equalization channel. The pressure equalization channel is thus at least partially formed in the circuit board or integrated in this. It extends from the second printed circuit board cavity, in particular from the cavity, starting up to an outer surface of the loudspeaker arrangement.

It is advantageous if the pressure equalization channel has a compensation opening for pressure equalization with the environment. This is preferably on the outer surface, preferably a side surface, a bottom and / or a top, the speaker assembly, in particular the circuit board, arranged. The compensation opening is preferably arranged at the end of the pressure equalization channel facing away from the cavity.

It is advantageous if the pressure compensation channel has a first section, in particular connected to the second circuit board cavity, and / or a second section, in particular connected to the compensation opening. Preferably, these are arranged at an angle to each other. In particular, a kink is formed between them. The two areas are preferably inclined to each other by an angle, in particular of 90 °.

Figur 1

ein erstes Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einem in der Leiterplatte integrierten ASIC und einer in der Leiterplatte integrierten Kavität,

Figur 2

ein zweites Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einem in der Leiterplatte integrierten ASIC und einer in der Leiterplatte integrierten Kavität und einem in der Leiterplatte integrierten MEMS-Lautsprecher,

Figur 3

ein drittes Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einem in der Leiterplatte integrierten ASIC und einer in der Leiterplatte integrierten Kavität, einem in der Leiterplatte integrierten MEMS-Lautsprecher und einem in der Leiterplatte integrierten Schallleitkanal,

Figur 4

ein viertes Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einer alternativen Orientierung des MEMS-Lautsprechers sowie einer alternativen Ausführungsform eines Druckausgleichskanals,

Figur 5

ein fünftes Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einer alternativen Ausführungsform des Schallleitkanals,

Figur 6

ein sechstes Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einer alternativen Ausführungsform des MEMS-Lautsprechers und

Figur 7

ein siebtes Ausführungsbeispiel der Lautsprecheranordnung in der Schnittansicht mit einer alternativen Ausführungsform des zweiten Leiterplattenhohlraums.

Further advantages of the invention are described in the following exemplary embodiments. It shows:

FIG. 1

a first embodiment of the loudspeaker arrangement in the sectional view with an ASIC integrated in the printed circuit board and a cavity integrated in the printed circuit board,

FIG. 2

A second embodiment of the loudspeaker arrangement in the sectional view with an ASIC integrated in the printed circuit board and a cavity integrated in the printed circuit board and a MEMS loudspeaker integrated in the printed circuit board,

FIG. 3

a third embodiment of the loudspeaker arrangement in the sectional view with an integrated ASIC in the circuit board and a built-in circuit board cavity, a built-in PCB in the MEMS speaker and a built-in PCB conductive sound channel,

FIG. 4

A fourth embodiment of the loudspeaker arrangement in the sectional view with an alternative orientation of the MEMS loudspeaker and an alternative embodiment of a pressure equalization channel,

FIG. 5

5 shows a fifth exemplary embodiment of the loudspeaker arrangement in the sectional view with an alternative embodiment of the sound conduction channel,

FIG. 6

a sixth embodiment of the speaker assembly in the sectional view with an alternative embodiment of the MEMS speaker and

FIG. 7

a seventh embodiment of the speaker assembly in the sectional view with an alternative embodiment of the second circuit board cavity.

In the following description of the figures, in order to define the relationships between the various elements, relative terms, such as above, below, above, below, above, below, left, right, vertically and above, are used with reference to the respective positions of the objects shown in the figures horizontal, used. It goes without saying that these terms may change in the event of a deviation from the position of the devices and / or elements shown in the figures. Accordingly, for example, in the case of an inverted orientation of the devices and / or elements shown in relation to the figures, a feature specified above in the following description of the figures would now be arranged underneath. The relative terms used thus merely serve to simplify the description of the relative relationships between the individual devices and / or elements described below. In the embodiments shown in the figures, a z-axis of a MEMS loudspeaker extends in its direction a membrane of the MEMS speaker is able to swing, vertically or between the bottom and top of the speaker assembly.

FIG. 1 shows a first embodiment of a speaker assembly 1 in a side sectional view. The loudspeaker arrangement 1 essentially comprises a printed circuit board 2, a MEMS loudspeaker 3 and an ASIC 4. The MEMS loudspeaker 3 is connected to the ASIC 4 with electrical contacts which are not shown in detail in the figures. The MEMS loudspeaker 3 can thus be controlled via the ASIC 4.

The MEMS loudspeaker 3 is designed such that it can generate sound waves in the audible wavelength spectrum. For this purpose, the MEMS loudspeaker 3 comprises a carrier substrate 5. The carrier substrate 5 has at least one substrate cavity 6. The substrate cavity 6 in turn has a first, image-oriented upper, substrate opening 7 and a second, image-oriented lower, substrate opening 8 in the area of two opposite sides of the carrier substrate 5. The carrier substrate 5 thus forms a frame. The MEMS loudspeaker 3 further comprises a membrane 9. This is connected in the edge region 10 of the carrier substrate 5 fixed thereto. The membrane 9 thus spans the frame-shaped carrier substrate 5 in the region of the first substrate opening 7. The MEMS loudspeaker 3 can be excited via the ASIC 4 in such a way that the membrane 9 is vibrated relative to the carrier substrate 5 in order to generate sound energy.

According to FIG. 1 For example, the circuit board 2 has a first circuit board cavity 11. The first circuit board cavity 11 is substantially completely closed. In the first circuit board cavity 11 of the ASIC 4 is arranged. The ASIC 4 is thus completely embedded in the printed circuit board 2.

In addition to the ASIC 4, the loudspeaker arrangement 1 has electrical, in particular passive, additional components 12a, 12b. This electronic Additional components 12a, 12b are likewise embedded in the printed circuit board 2. According to the in FIG. 1 illustrated embodiment, these are arranged in the same first printed circuit board cavity 11. Alternatively, however, the first printed circuit board cavity 11 could also comprise a plurality of separate printed circuit board cavities, wherein an electronic component, ie the ASIC 4 and / or an additional component 12a, 12b, could be arranged separately in each one. It is advantageous if these printed circuit board cavities are arranged in a plane of the loudspeaker arrangement 1.

In addition to the first circuit board cavity 11, the circuit board 2 comprises a second circuit board cavity 13. The second circuit board cavity 13 has an opening 14. This is closed by the MEMS loudspeaker 3. For this purpose, the MEMS loudspeaker 3 extends over at least the entire width of the opening 14. In this way, the second printed circuit board cavity 13 forms part of a cavity 15 of the MEMS loudspeaker 3. The cavity 15 serves to increase the sound pressure of the MEMS loudspeaker 3. Due to the installation position of the MEMS speaker 3, the other part of the cavity 15 is formed by the substrate cavity 6 of the MEMS speaker 3. The cavity 15 of the MEMS speaker 3 is in accordance with the in FIG. 1 illustrated embodiment thus formed very large, since this is formed both by the second circuit board cavity 13 and by the substrate cavity 6.

In order to be able to ensure a pressure equalization between the cavity 15 and the surroundings during oscillation of the membrane 9, the loudspeaker arrangement 1 has at least one pressure equalization channel 16a, 16b, wherein the in FIG. 1 illustrated embodiment comprises a first and second pressure equalization channel 16a, 16b. The two pressure equalization channels 16a, 16b are formed in the printed circuit board 2. They both extend from the second printed circuit board cavity 13 up to an outer side surface 17a, 17b of the printed circuit board 2. On this outer surface of the printed circuit board 2, in this case the side surface 17a, 17b, have the pressure equalization channels 16a, 16b each have a compensation opening 18a, 18b. For pressure equalization, air can flow out of the second printed circuit board cavity 13 via the pressure equalization channels 16a, 16b from the printed circuit board 2 when the membrane 9 is lowered. In an analogous manner, however, air can also flow into the second printed circuit board cavity 13 via the pressure equalization channels 16a, 16b when the membrane 9 is raised. According to the in FIG. 1 illustrated embodiment, both flow channels 16a, 16b, in particular coaxially to each other, extend in the transverse direction of the printed circuit board second

According to FIG. 1 is the opening 14 of the second circuit board cavity 13 on the outside of the circuit board 2, in this case the built-in top 19 of the circuit board 2 is formed. For completely closing this opening 14 is according to FIG. 1 Thus, the MEMS speaker 3 on the outside or top 19 of the circuit board 2 is arranged. In this case, the MEMS loudspeaker 3 is oriented in such a way relative to the printed circuit board 2 that its second substrate opening 8 points towards the printed circuit board 2. As a result, the volume of the cavity 15 can be increased since the cavity 15 now also includes the substrate cavity 6 in addition to the second printed circuit board cavity 13.

The MEMS speaker 3 may be glued to the circuit board 2. Additionally or alternatively, this according to FIG. 1 but also by a protective layer 20 material and / or positively connected to the circuit board 2. The protective layer 20 is formed on the upper side 19 of the printed circuit board 2 and extends in the transverse direction of the loudspeaker arrangement 1 into the edge region 10 of the MEMS loudspeaker 3. As a result, the MEMS loudspeaker 3 is firmly connected to the printed circuit board 2.

The loudspeaker arrangement 1 furthermore comprises a sound-conducting channel 21 of the side of the MEMS loudspeaker 3 facing away from the second printed circuit board cavity 13 up to an outer surface of the loudspeaker arrangement 1 extends. On the outer surface of the loudspeaker arrangement 1, the sound-conducting channel 21 has an acoustic outlet opening 22.

The integrally formed in the printed circuit board 2 ASIC 4 and integrating in the circuit board 2 training at least a portion of the cavity 15, the speaker assembly 1 can be made very compact. Furthermore, the speaker assembly 1 is very inexpensive to produce, especially since the circuit board 2 is sandwiched. The printed circuit board 2 therefore comprises a plurality of layers 23 arranged one above the other and / or interconnected, of which only one is provided with a reference numeral for the sake of clarity. The layers 23 are firmly connected to each other. Some of these layers 23 have at least one recess 24, by means of which height at least partially one of the printed circuit board cavities 11, 13 is formed.

In this case, the layers 23 may be selected to be so thick that even a single one has a corresponding height for forming the respective printed circuit board cavity 11, 13. Alternatively, however, it is also conceivable that a plurality of such layers 23, in particular with an identically formed and / or mutually congruently arranged recess 24, are stacked one above the other until the desired height for the respective printed circuit board cavity 11, 13 is reached.

According to FIG. 1 the first and second printed circuit board cavity 11, 13 are arranged one above the other. In the region between the first printed circuit board cavity 11 and the second printed circuit board cavity 13, the printed circuit board 2 has at least one continuous layer, ie without recess 24, so that the two printed circuit board cavities 11, 13 are separated from one another.

In the FIGS. 2 to 7 Further embodiments of the loudspeaker arrangement 1 are shown, wherein in each case substantially the differences with respect to the embodiments already described are discussed. So In the following description of the further embodiments, the same reference signs are used for the same features. Unless these are explained again in detail, their design and mode of action corresponds to the features already described above. The differences described below can be combined with the features of the respective preceding and following embodiments.

Unlike the in FIG. 1 illustrated embodiment is in the in FIG. 2 illustrated embodiment, in addition, the MEMS speaker 3 integrated into the circuit board 2. For this purpose, the circuit board 2 on a third circuit board cavity 25. This third circuit board cavity 25 is formed adjacent and / or according to the illustrated orientation of the speaker assembly 1 above the second circuit board cavity 13. According to the present embodiment, the third circuit board cavity 25 has a larger width compared to the second circuit board cavity 13. This width substantially corresponds to the width of the MEMS loudspeaker 3. The MEMS loudspeaker 3 is arranged in the third printed circuit board cavity 25 and consequently completely embedded in the printed circuit board 2.

Due to the width differences between the second and third circuit board cavity 13, 25 in the transverse direction of the loudspeaker arrangement 1, a projection 26 is formed between the two, by means of which the position of the MEMS loudspeaker 3 in the circuit board 2 is fixed in the Z direction.

The loudspeaker arrangement 1 does not necessarily require a protective layer 20 as shown in the exemplary embodiment illustrated in FIG. 1, since the MEMS loudspeaker 3 is positively positioned in the printed circuit board 2 and held in a form-fitting manner in the transverse direction as well as in the downward direction. In order to avoid falling out of the MEMS speaker 3 from the third PCB cavity 25, the MEMS speaker 3 is in the third Printed circuit board cavity 25 glued and / or non-positively pressed into this.

The third printed circuit board cavity 25 is formed by at least one additional layer 23 of the printed circuit board 2. According to the above description, the third circuit board cavity 25 may be formed analogously to the first and second circuit board cavities 11, 13 by a single layer 23 comprising a recess 24. Alternatively, however, it is also possible to connect several layers 23 with mutually congruent recesses 24 one above the other.

According to FIG. 2 the MEMS loudspeaker 3 terminates flush with the upper side 19 of the printed circuit board 2. Alternatively, the height of the third circuit board cavity 25 compared to the height of the MEMS speaker 3 but also be designed to be larger, so that the MEMS speaker 3 to the top 19 of the circuit board 2 has a distance.

In addition to the in FIG. 2 illustrated embodiment, the in FIG. 3 illustrated embodiment, a fourth circuit board cavity 27. The fourth circuit board cavity 27 is formed adjacent and / or above the third circuit board cavity 25. The fourth printed circuit board cavity 27 is consequently formed on a side of the third printed circuit board cavity 25 facing away from the second printed circuit board cavity 13. The fourth printed circuit board cavity 27 thus forms the sound conducting channel 21 of the loudspeaker arrangement 1. According to the in FIG. 1 illustrated embodiment, the Schallleitkanal 21 extends to the outer surface of the circuit board 2 out. In the present case, the sound conducting channel 21, which is completely formed by the fourth printed circuit board cavity 27 of the printed circuit board 2, is conically shaped.

The fourth circuit board cavity 27 has a smaller width compared to the third circuit board cavity 25. Compared to the second and fourth circuit board cavities 13, 27, the third circuit board cavity 25 thus a larger width. As a result, the MEMS loudspeaker 3 is gripped positively in its edge region 10 by the printed circuit board 2. The MEMS loudspeaker 3 is thus held firmly in the third printed circuit board cavity 25 by means of positive locking.

The second and fourth circuit board cavities 13, 27 are spaced from each other by means of the third circuit board cavity 25. Further, these are separated from each other by the MEMS speaker 3 integrated in the third circuit board cavity 25.

In the in FIG. 3 illustrated embodiment, the fourth circuit board cavity 27 is analogous to the first, second and third circuit board cavity 11, 13, 25 formed by at least one layer 23 of the circuit board 2, which has a correspondingly wide recess 24 for forming the fourth circuit board cavity 27. In the sense of the preceding description, it is of course also possible for the formation of the fourth circuit board cavity 27 to have a plurality of layers 23 with corresponding recesses 24 arranged one above the other.

According to the in the FIGS. 1, 2 and 3 illustrated embodiment of the speaker assembly 1, the MEMS speaker 3 relative to the circuit board 2 is oriented such that the substrate cavity 6 and the second circuit board cavity 13 together form the cavity 15 of the MEMS speaker 3. For this purpose, the second substrate opening 8 is oriented toward the second printed circuit board cavity 13. Alternatively, however, the MEMS loudspeaker 3 can also be arranged rotated through 180 ° in the printed circuit board 2. According to the in FIG. 4 illustrated embodiment, the MEMS speaker 3 relative to the circuit board 2 is thus oriented so that the substrate cavity 6 together with the fourth printed circuit board cavity 27 form the Schallleitkanal 21.

Another difference of in FIG. 4 illustrated embodiment is that the second pressure equalization channel 16b of the second circuit board cavity 13 does not extend to the side surface 17b, but to the top 19 of the circuit board 2. The second pressure equalization channel 16b has for this purpose a first and second section 28, 29. The first portion 28 is connected to the second circuit board cavity 13. The second section 29 has at its end the compensation opening 18b. The two sections 28, 29 are inclined to each other by an angle of 90 °. Alternatively, it is also conceivable that the pressure equalization channel 16b is formed bent to exit at the top 19 of the circuit board 2 accordingly.

According to the in FIG. 5 illustrated embodiment, the outlet opening 22 of the Schallleitkanals 21 may also be formed on a side surface 17b of the printed circuit board 2. For this purpose, the sound transmission channel 21 or, according to the present exemplary embodiment, in particular the fourth printed circuit board cavity 27 has a first region 30 adjacent to the MEMS loudspeaker 3 and a second region 31 adjacent to the outlet opening 22. The two areas 30, 31 are inclined relative to one another in such a way that the sound emitted upward by the MEMS loudspeaker 3 is deflected to the side face 17b of the printed circuit board 2 and exits laterally from the printed circuit board 2 through the outlet opening 22. In an alternative embodiment, not shown here, the Schallleitkanal 21 but only according to FIG. 5 horizontally extending region 31 include. The sound channel 21 or region 31 extending at a 90 ° angle to the z-axis would thus be arranged directly adjacent to the MEMS loudspeaker 3. Additionally or alternatively, the fourth cavity 27 may also be formed in an attachment 36 separate from the printed circuit board 2. This separate attachment 36 is then connected to the circuit board 2, in particular glued. In this case, the attachment 36 has a different material to the circuit board 2. According to FIG. 5 Thus, the ASIC 4 and the MEMS speaker in the circuit board 2 is integrated or embedded and / or the circuit board. 2 separate attachment 36 comprises at least partially, in the present case completely, the sound-conducting channel 21, preferably the first and / or the second region 30, 31.

According to the in FIG. 5 illustrated embodiment, the Schallleitkanal 21 and / or the outlet opening 22 may thus be formed in the printed circuit board 2 or alternatively in a separate to the circuit board 2 attachment 36. The sound transmission channel 21 extends at least partially at an angle to the z axis of the MEMS loudspeaker 3, so that the sound waves generated by the MEMS loudspeaker 3 are deflected by the sound conduction channel 21. The outlet opening 22 is arranged laterally on the loudspeaker arrangement 1, in particular on a side surface 17b which is inclined by 90 ° with respect to the z-axis.

FIG. 6 shows the speaker assembly 1 with an alternative embodiment of the MEMS loudspeaker 3. Here, the MEMS loudspeaker 3 is formed with a plurality of sound-generating membrane regions 32, of which only one is provided with a reference numeral for the sake of clarity. Each of these membrane regions 32 is assigned its own substrate cavity 6. The substrate cavities 6 are separated from one another by webs 33. According to the in FIG. 6 illustrated embodiment, all substrate cavities 6 open into the common second circuit board cavity thirteenth

Alternatively, according to the embodiment shown in FIG. 7, however, the second circuit board cavity 13 may also have a plurality of cavity regions 35. These are formed by partition walls 34 extending into the second printed circuit board cavity 13. In this case, in each case one of the cavity regions 35 is assigned to a substrate cavity 6 of the MEMS loudspeaker 3. The partitions 34 are aligned coaxially with the respective corresponding web 33.

With the exception of in FIG. 1 1, the MEMS loudspeaker 3 is completely integrated in the printed circuit board 2 in all other embodiments. At the in FIG. 3, 4 . 5, 6 and 7 variants shown, the MEMS speaker 3 is additionally encompassed form-fitting from above. The scope of the invention is determined by the appended claims. All embodiments which do not fall within the scope of the appended claims are examples which facilitate the understanding of the invention.

The present invention is not limited to the illustrated and described embodiments. Variations within the scope of the claims are also possible as a combination of features, even if they are shown and described in different embodiments.

LIST OF REFERENCE NUMBERS

1.

Speaker layout

Second

circuit board

Third

MEMS speakers

4th

ASIC

5th

carrier substrate

6th

substrate cavity

7th

first substrate opening

8th.

second substrate opening

9th

membrane

10th

border area

11th

first PCB cavity

12th

passive additional components

13th

second PCB cavity

14th

opening

15th

cavity

16th

Pressure compensation channel

17th

side surface

18th

compensation opening

19th

top

20th

protective layer

21st

Schallleitkanal

22nd

outlet opening

23rd

layer

24th

recess

25th

third circuit board cavity

26th

head Start

27th

fourth PCB cavity

28th

first section

29th

second part

30th

first area

31st

second area

32nd

membrane region

33rd

web

34th

partition wall

35th

cavity region

36th

attachment

Claims (13)

1. Loudspeaker array (1)
   comprising a circuit board (2),
   a MEMS loudspeaker (3), which is intended for generating sound waves in the audible wavelength range, and which has a diaphragm (9) deflectable along a Z axis, and
   an ASIC (4), which is electrically connected to the MEMS loudspeaker (3),
   wherein the circuit board (2) has a first circuit board cavity (11), in which the ASIC (4) is arranged, and
   that the circuit board (2) has a second circuit board cavity (13) having an opening (14),
   which is closed by means of the MEMS loudspeaker (3), so that the second circuit board cavity (13) forms at least a part of a cavity (15) of the MEMS loudspeaker (3),
   characterized in that
   the first circuit board cavity (11) is closed, so that the ASIC (4) is completely integrated and embedded into the circuit board (2), and the loudspeaker array (1) has a sound-conducting channel (21), adjacent to the MEMS loudspeaker (3), comprising an acoustic outlet opening (22),
   the sound-conducting channel (21) extends oblique to the Z axis of the MEMS loudspeaker and
   the acoustic outlet opening (22) is arranged on a side face of the loudspeaker array (1).
2. Loudspeaker array, as claimed in the preceding claim, characterized in that the sound-conducting channel (21) is inclined by 90°.
3. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the circuit board (2) has a third circuit board cavity (25), which is adjacent, in particular, to the second circuit board cavity (13) and/or is arranged in the region of the opening (14), and the MEMS loudspeaker (3) is disposed at least partially in said third circuit board cavity (25).
4. Loudspeaker array, as claimed in claim 3, characterized in that the MEMS loudspeaker (3) is integrated into the circuit board (2), in particular, in such a way that the third circuit board cavity (25) envelops in a form-fitting manner the MEMS loudspeaker (3) in its edge region (10), in particular, in the region of its side facing the second circuit board cavity (13).
5. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the sound-conducting channel (21) is arranged adjacent to the third circuit board cavity (25) and/or is formed at least partially by a fourth circuit board cavity (27) of the circuit board (2).
6. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the width of the sound-conducting channel (21) at least in regions enlarges in the direction of the outlet opening (22).
7. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the sound-conducting channel (21) comprises a first region (30) and a second region (31) and said first and second regions (30, 31) are inclined with respect to each other at an angle, in particular of 90°.
8. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the second and fourth circuit board cavities (13, 27) are spaced apart from one another by means of the third circuit board cavity (25) and/or are separated from one another by means of the MEMS loudspeaker (3) integrated therein.
9. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the circuit board (2) is constructed like a sandwich of several layers (23), which are connected to each other and of which
   at least one layer (23) has a first recess (24), by means of which the first circuit board cavity (11) is formed at least partially, and/or
   has a second recess (24), by means of which the second, third and/or fourth circuit board cavity/cavities (13, 25, 27) is/are formed at least partially.
10. Loudspeaker array, as claimed in one or more of the preceding claims, characterized in that the first and second circuit board cavities (11, 13) are arranged side by side or one on top of the other and/or are separated from each other.
11. Loudspeaker array as claimed in one or more of the preceding claims, characterized in that the circuit board (2) has at least one pressure equalization channel (16), which extends, starting from the second circuit board cavity (13), up to an outer face of the loudspeaker array (1).
12. Loudspeaker array, as claimed in claim 11, characterized in that the pressure equalization channel (16) has an equalization opening (18) on the outer face, preferably, a side face, a bottom side and/or a top side, of the loudspeaker array (1), in particular, the circuit board (2).
13. Loudspeaker array, as claimed in claims 11 or 12, characterized in that the pressure equalization channel (16) has a first section (28), which is connected, in particular, to the second circuit board cavity (13), and a second section (29), which is connected, in particular, to the equalization opening (18), and both the first and second sections (28, 29) are inclined with respect to each other, preferably at an angle, in particular of 90°.

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