Microphone assembly and method for manufacturing a microphone assembly

Abstract

Microphone assembly (1) comprising at least one microphone capsule (2), preferably a MEMS microphone capsule, wherein the microphone assembly (1) comprises at least one electrical contacting means (3) for supplying voltage and / or for providing microphone signals, wherein the microphone assembly (1) comprises a first printed circuit board (4), on the upper side (5) of which the microphone capsule (2) is arranged, preferably fastened, wherein the first printed circuit board (4) comprises through-openings (6, 6a), characterized in that a bottom side (7) of the first circuit board (4) is connected to a second circuit board (9) comprising through-openings (8, 8a) in such a way that through-openings (6, 6a) of the first circuit board (4) and through-openings (8, 8a) of the second circuit board (9) form channels (10, 10a) designed for the passage of sound waves, and Channels (10, 10a) are formed which are spatially separated from one another by a web (11) arranged in the first circuit board (4) and a web (12) arranged in the second circuit board (9).

Description

[0001] The invention relates to a microphone assembly according to the preamble of claim 1 and to a method for producing a microphone assembly according to the preamble of claim 12.

[0002] Microphone assemblies are already known from the prior art. For example, US 2010 / 0142743 A1 discloses a microphone assembly in which a MEMS microphone capsule is arranged in a separate housing with delay channels. The housing is mounted on a circuit board that has sound outlet openings. This known microphone assembly has the disadvantage of being bulky and requiring a correspondingly large amount of space. Furthermore, this known microphone assembly is very difficult to manufacture and, due to its size and design, is unsuitable for various applications.

[0003] From DE 10 2014 108 962 A1, WO 2007129787 A1, DE 10 2010 030 457 A1, WO 2017012122 A1 and US 2010142743 A1, microphone assemblies are known which have printed circuit boards, microphone capsules and openings for sound waves.

[0004] The object of the invention is to provide a particularly compact microphone assembly which can be used for various applications and can be manufactured particularly cost-effectively.

[0005] To achieve the object, a microphone assembly is proposed, comprising at least one microphone capsule, preferably a MEMS microphone capsule, wherein the microphone assembly comprises at least one electrical contacting means for supplying voltage and / or for providing microphone signals, wherein the microphone assembly comprises a first printed circuit board, on the upper side of which the microphone capsule is arranged, preferably fastened, wherein the first printed circuit board comprises through openings.

[0006] Essential to the invention is that an underside of the first circuit board is connected to a second circuit board comprising through-openings such that the through-openings of the first circuit board and the through-openings of the second circuit board form channels designed for the penetration of sound waves. In this way, a particularly compact microphone assembly can be provided that can be produced cost-effectively.

[0007] The acoustic properties of the microphone assembly can also be optimized since it is provided that channels are formed which are spatially separated from one another by a web arranged in the first circuit board and a web arranged in the second circuit board.

[0008] In order to enable particularly simple provision of a channel and, at the same time, to provide a particularly compact microphone assembly, a particularly advantageous embodiment of the invention can provide through-openings in the second circuit board as elongated holes. A further advantage of this is that such a microphone assembly has particularly good acoustic properties.

[0009] In order to be able to obtain a compact microphone assembly with good acoustic properties, a further advantageous embodiment of the invention can provide that through-openings of the first circuit board are designed as cylindrical holes.

[0010] The invention can also provide that the second printed circuit board comprises, on a bottom side, a covering means comprising through-openings for forming the channels, which through-openings are arranged adjacent to the channels, preferably at least partially congruent with through-openings of the second printed circuit board.

[0011] In a further development of the invention, sound-permeable cover elements for covering the through-openings of the cover can be arranged on an underside of the cover. The acoustic properties of the microphone assembly can thus be positively influenced.

[0012] In order to further positively influence the acoustic properties of the microphone assembly, an advantageous embodiment of the invention can provide that the sound-permeable cover elements have different delay properties for generating an acoustic directional characteristic.

[0013] The acoustic properties of the microphone assembly can also be positively influenced by having different lengths of the channels to generate an acoustic directional characteristic.

[0014] In a further development of the invention, the covering means and the covering elements can be designed as a joined, in particular glued, unit. This can reduce the manufacturing effort of the microphone assembly.

[0015] An advantageous embodiment of the invention can provide that the at least one contacting means comprises pin contacts arranged on the first circuit board and / or on the second circuit board, and that the at least one contacting means comprises a plug connector that is positively connected to the first circuit board and / or to the second circuit board. This enables a stable attachment of the plug connector to the circuit board. Furthermore, the microphone assembly can be designed more compactly.

[0016] In order to be able to connect or replace a connector easily and quickly, a further advantageous embodiment of the invention can provide that the first circuit board and / or the second circuit board comprises a preferably groove-shaped locking means for releasably fastening the connector to the first circuit board.

[0017] In a particularly advantageous development of the invention, it can be provided that means for signal processing are formed on an underside of the first circuit board, which are arranged at least partially in through-openings of the second circuit board. This makes it possible, on the one hand, to require only one circuit board to provide the microphone assembly, which can result in corresponding savings in production. On the other hand, the compactness of the microphone assembly can be further increased. Another advantage is that IP and ESD protection are also ensured.

[0018] The invention also relates to an acoustic array comprising at least two microphone assemblies, wherein the invention provides that the at least two microphone assemblies are designed according to one or more of claims 1 to 10. Such an array is particularly compact and can be manufactured cost-effectively. Furthermore, an array according to the invention has very good acoustic properties and is versatile in its application, e.g., for level amplification, beam forming, etc.

[0019] The invention further relates to a method for producing a microphone assembly, which according to the invention comprises the following steps: a) Attaching a microphone capsule, preferably a MEMS microphone capsule, to an upper side of a first circuit board comprising through-openings. b) fastening the first circuit board to a second circuit board comprising through-openings, in particular elongated holes, in such a way that through-openings of the first circuit board and through-openings, preferably elongated holes, of the second circuit board are arranged congruently at least in sections and form channels, wherein channels (10, 10a) are formed which are spatially separated from one another by a web (11) arranged in the first circuit board (4) and a web (12) arranged in the second circuit board (9). c) Attaching a covering means comprising through-openings to an underside of the second printed circuit board in such a way that the through-openings of the covering means and through-openings of the second printed circuit board, preferably elongated holes, are arranged congruently at least in sections.

[0020] This allows for a particularly compact microphone assembly. A particular advantage is that, apart from the microphone capsule and the electrical contacts, all materials are available by the meter and can be used accordingly, significantly reducing manufacturing costs. The process is also characterized by high process reliability.

[0021] In an advantageous further development, the procedure is characterized by a further step: d) Attaching sound-permeable cover elements, preferably with different delay properties, to generate a directional characteristic on an underside of the cover means, which takes place after step c).

[0022] In this way, the acoustic properties of the microphone assembly can be improved. It is equally advantageous that sound-permeable cover elements are available by the meter and can be used accordingly, significantly reducing manufacturing costs.

[0023] A further development of the method can provide for the covering means and the covering elements to be glued together to produce a first assembly. Such assemblies can be prefabricated by the meter or purchased particularly cost-effectively. The manufacturing costs for the microphone assembly can thus be kept low. A further development of the method can also provide for the first assembly to be connected to the second circuit board. This can significantly simplify the production of the microphone assembly.

[0024] In an advantageous embodiment, the method can provide that for the production of a second assembly - in a first step, the microphone capsule is soldered onto the first circuit board, preferably by reflow soldering, and - in a second step, the first circuit board is soldered onto the second circuit board, preferably by reflow soldering.

[0025] The first step and the second step can also be carried out in one step, which further simplifies the process.

[0026] Reflow soldering is a simple, reliable and cost-effective way to connect printed circuit boards or between a printed circuit board and a microphone capsule.

[0027] An advantageous development of the method can provide for channels of different lengths to be formed to generate an acoustic directional characteristic. This can positively influence the acoustic properties of the microphone assembly.

[0028] The invention is explained in more detail below with reference to the drawings. Herein: Fig. 1: a schematic representation of an embodiment of a microphone assembly according to the invention in an exploded view; Fig. 2: a schematic representation of a section of an embodiment of a microphone assembly according to the invention in a sectional view; Fig. 3: a schematic representation of a section of a further embodiment of a microphone assembly according to the invention in a sectional view; Fig. 4: a schematic representation of a further embodiment of a microphone assembly according to the invention in an exploded view; Fig. 5: a schematic representation of an embodiment of an acoustic array according to the invention.

[0029] In the Fig. Figure 1 shows a schematic exploded view of an embodiment of a microphone assembly 1 according to the invention. The microphone assembly 1 comprises a microphone capsule 2, which is embodied as a MEMS microphone capsule. Furthermore, the microphone assembly 1 comprises at least one electrical contacting means 3 for supplying power and / or providing microphone signals. The contacting means 3 comprises pin contacts 18, 18a, 18b, 18c, 18d, 18e.

[0030] The microphone assembly 1 further comprises a first circuit board 4, on the top side 5 of which the microphone capsule 2 is arranged. The first circuit board 4 comprises through-openings 6, 6a (see Fig. 2). A bottom side 7 of the first circuit board 4 is connected to a second circuit board 9 comprising through-openings 8, 8a in such a way that through-openings 6, 6a of the first circuit board 4 and through-openings 8, 8a of the second circuit board 9 form channels 10, 10a designed for the passage of sound waves (see Fig. 2). In the embodiment according to Fig. 1, the through-openings 8, 8a of the second circuit board 9 are designed as elongated holes, and the through-openings 6, 6a of the first circuit board 4 are designed as cylindrical holes. The second circuit board 9 comprises, on a bottom side 13, a covering means 15 comprising through-openings 14, 14a for forming the channels 10, 10a, which through-openings 14, 14a are formed on the channels 10, 10a (see Fig. 2) are arranged congruently with through openings 8, 8a of the second circuit board 9.

[0031] Furthermore, Fig. 1 shows that sound-permeable cover elements 16, 16a are arranged on an underside 17 of the cover means 15 to cover the passage openings 14, 14a of the cover means 15. It is advantageous if the cover elements 16, 16a have different propagation time characteristics with respect to sound waves in order to create an acoustic directional characteristic.

[0032] The covering means 15 and the covering elements 16, 16a can be formed as a first assembly 24. The microphone capsule 2, first circuit board 4, and second circuit board 9 can be formed as a second assembly 25. In the second assembly 25, the underside 7 of the first circuit board 4 is connected to a top side 27 of the second circuit board 9.

[0033] For better understanding, the Fig. 2 shows a top side 22 of the microphone assembly 1 and a bottom side 23 of the microphone assembly 1. The microphone capsule 2 is arranged on the top side 22.

[0034] Out of Fig. 2 also shows that channels 10, 10a are formed, which are spatially separated from each other by a web 11 arranged in the first circuit board 4 and a web 12 arranged in the second circuit board 9. In the exemplary embodiment, two channels 10, 10a are formed.

[0035] In the embodiment according to Fig. 3, signal processing means 21, 21a, 21b, 21c, 21d are formed on the underside 7 of the first circuit board 4. The signal processing means 21, 21a, 21b, 21c, 21d are partially arranged in through-openings 28, 28a of the second circuit board 9. For reasons of simplified representation, means 21, 21a, 21b, 21c, 21d are shown only in the through-opening 28.

[0036] The first printed circuit board 4 can thus comprise further through-openings 28, 28a for arranging the signal processing means 21, 21a, 21b, 21c, 21d (see Fig. 4). The through-openings 28, 28a are designed as elongated holes.

[0037] The embodiment according to Fig. 4 shows that the first circuit board 4 comprises a groove-shaped locking means 20 for releasably fastening a connector 19 to the first circuit board 4. In the Fig. Figure 4 also schematically shows the lengths 29, 29a of the channels 10, 10a. The channels 10, 10a can have different lengths 29, 29a to create a directional pattern.

[0038] An acoustic array 26, which comprises several - in this case seven - microphone assemblies 1, is in Fig. 5 shown.

[0039] In a further embodiment of the invention, it can be provided that the first circuit board and the second circuit board are joined, in particular glued. The first and second circuit boards can be made of different materials; in particular, the second circuit board can also be made of plastic, for example. List of reference symbols: 1 microphone assembly 2 microphone capsules 3 Contact agents 4 First circuit board 5 Top side (of the first circuit board) 6 Passage opening 6a Passage opening 7 Bottom side (of the first circuit board) 8 Passage opening 8a Passage opening 9 Second circuit board 10 channel 10a Canal 11 jetty 12 jetty 13 Bottom side (of the second circuit board) 14 Passage opening 14a Passage opening 15 covering agents 16 Cover element 16a Cover element 17 Underside (of the covering agent) 18 pin contact 18a pin contact 18b pin contact 18c pin contact 18d pin contact 18e pin contact 19 connectors 20 rest stops 21 means (for signal processing) 21a Means (for signal processing) 21b Means (for signal processing) 21c Means (for signal processing) 21d Means (for signal processing) 22 Top (of the microphone assembly) 23 Bottom (of the microphone assembly) 24 First assembly 25 Second assembly 26 arrays 27 Top side (of the second circuit board) 28 Passage opening 28a Passage opening 29 length 29a length

Claims

[1] Microphone assembly (1) comprising at least one microphone capsule (2), preferably a MEMS microphone capsule, wherein the microphone assembly (1) comprises at least one electrical contacting means (3) for supplying voltage and / or for providing microphone signals, wherein the microphone assembly (1) comprises a first printed circuit board (4), on the upper side (5) of which the microphone capsule (2) is arranged, preferably fastened, wherein the first printed circuit board (4) comprises through-openings (6, 6a), characterized by , that a bottom side (7) of the first circuit board (4) is connected to a second circuit board (9) comprising through-openings (8, 8a) in such a way that through-openings (6, 6a) of the first circuit board (4) and through-openings (8, 8a) of the second circuit board (9) form channels (10, 10a) designed for the passage of sound waves, and Channels (10, 10a) are formed which are spatially separated from one another by a web (11) arranged in the first circuit board (4) and a web (12) arranged in the second circuit board (9). [2] Microphone assembly (1) according to claim 1, characterized by that through openings (8, 8a) of the second circuit board (9) are designed as elongated holes. [3] Microphone assembly (1) according to one of the preceding claims, characterized by that through openings (6, 6a) of the first printed circuit board (4) are designed as cylindrical holes. [4] Microphone assembly (1) according to one of the preceding claims, characterized bythat the second printed circuit board (9) comprises on a bottom side (13) a covering means (15) comprising through-openings (14, 14a) for forming the channels (10, 10a), which through-openings (14, 14a) are arranged adjacent to the channels (10, 10a), preferably at least partially congruent with through-openings (8, 8a) of the second printed circuit board (9). [5] Microphone assembly (1) according to claim 4, characterized by that sound-permeable cover elements (16, 16a) for covering the passage openings (14, 14a) of the cover means (15) are arranged on an underside (17) of the cover means (15). [6] Microphone assembly (1) according to claim 4 or 5, characterized by that the sound-permeable cover elements (16, 16a) have different delay properties for generating an acoustic directional characteristic. [7] Microphone assembly (1) according to one of the preceding claims, characterized bythat the channels (10, 10a) have different lengths (29, 29a) for generating an acoustic directional characteristic. [8] Microphone assembly (1) according to claim 4 or 5, characterized by that the covering means (15) and the covering elements (16, 16a) are designed as an assembled, in particular glued, structural unit. [9] Microphone assembly (1) according to one of the preceding claims, characterized by that the at least one contacting means (3) comprises pin contacts (18, 18a, 18b, 18c, 18d, 18e) which are arranged on the first circuit board (4) and / or on the second circuit board (9), and that the at least one contacting means (3) comprises a plug connector (19) which is positively connected to the first circuit board (4) and / or to the second circuit board (9). [10] Microphone assembly (1) according to claim 9, characterized bythat the first circuit board (4) and / or the second circuit board (9) comprises a preferably groove-shaped locking means (20) for releasably fastening the plug connector (19) to the first circuit board (4). [11] Microphone assembly (1) according to one of the preceding claims, characterized by that means for signal processing (21, 21a, 21b, 21c, 21d) are formed on an underside (7) of the first printed circuit board (4), which means are arranged at least partially in through-openings (28, 28a), preferably elongated holes, of the second printed circuit board (9). [12] Method for producing a microphone assembly (1), characterized by following steps: a) fastening a microphone capsule (2), preferably a MEMS microphone capsule, to an upper side (5) of a first printed circuit board (4) comprising through-openings (6, 6a); b) fastening the first circuit board (4) to a second circuit board (9) comprising through-openings (8, 8a), in particular elongated holes, in such a way that through-openings (6, 6a) of the first circuit board (4) and through-openings (8, 8a), preferably elongated holes, of the second circuit board (9) are arranged congruently at least in sections and form channels (10, 10a), wherein channels (10, 10a) are formed which are spatially separated from one another by a web (11) arranged in the first circuit board (4) and a web (12) arranged in the second circuit board (9); c) Attaching a covering means (15) comprising through-openings (14, 14a) to an underside (13) of the second printed circuit board (9) in such a way that the through-openings (14, 14a) of the covering means (15) and through-openings (8, 8a) of the second printed circuit board (9), preferably elongated holes, are arranged congruently at least in sections. [13] Method according to claim 12, characterized by one more step: d) Attaching sound-permeable cover elements (16, 16a), preferably with different delay properties, to produce a directional characteristic on an underside (17) of the cover means (15), which takes place after step c). [14] Method according to claim 12 or 13, characterized by that channels (10, 10a) with different lengths (29, 29a) are formed to generate an acoustic directional characteristic.

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