Microphone Device with a Closed Housing and a Membrane

Abstract

The disclosure relates to a microphone device. The microphone device comprises a closed housing with a sidewall, a microphone arranged within the closed housing, and a membrane at an outer surface of the sidewall wherein a first part of the sidewall has a first thickness and wherein the membrane is comprised by, in particular is formed by, a second part of the sidewall having a second thickness smaller than the first thickness. The disclosure further relates to a method for generating the microphone device. The microphone device protects the microphone from water or particles at high protection level.

Claims

1. A microphone device comprising: a closed housing with a sidewall; and a microphone arranged within the closed housing; and a membrane at an outer surface of the sidewall, wherein a first part of the sidewall has a first thickness and wherein the membrane is comprised by, in particular is formed by, a second part of the sidewall having a second thickness that is smaller than the first thickness.

2. The microphone device of claim 1 further comprising: a cavity arranged between the membrane and the microphone, wherein the second part of the sidewall is arranged adjacent to the cavity, or wherein the cavity is arranged within the sidewall.

3. The microphone device of claim 2, wherein the membrane covers the cavity.

4. The microphone device of claim 2 further comprising at least one support element, wherein the at least one support element retains the microphone at a fixed position relative to at least one of the housing or the sidewall of the housing.

5. The microphone device of claim 4, wherein the cavity is confined by the sidewall of the closed housing, or wherein the cavity is confined by the second part of the sidewall of the housing, and the at least one support element.

6. The microphone device of claim 4, wherein the at least one support element seals the cavity against an inner space of the housing.

7. The microphone device of claim 4, wherein at least a part of the at least one support element is embedded within the cavity of sidewall of the housing.

8. The microphone device of claim 4, wherein the microphone is at least one of arranged on the at least one support element opposite the membrane or adjacent to the cavity, and wherein the at least one support element comprises an opening between the cavity and the microphone.

9. The microphone device of claim 4, wherein at least one of the cavity or the at least one support element has a conical or cylindrical shape.

10. The microphone device of claim 4, wherein the at least one support element is made of plastic or rubber.

11. The microphone device of claim 1 comprising a plurality of microphones arranged as a microphone array.

12. The microphone device of claim 11, wherein each of the microphones of the microphone array is opposed by one of a respective one of a plurality of membranes or a respective one of a plurality of cavities.

13. A method for generating a microphone device, the method comprising: providing a closed housing with a sidewall; providing a membrane at an outer surface of the sidewall; and placing a microphone within the housing and opposite the membrane; wherein a first part of the sidewall has a first thickness, and wherein the membrane is formed by a second part of the sidewall having a second thickness smaller than the first thickness.

14. The method of claim 13 further comprising: forming a cavity within the sidewall of the closed housing, wherein the cavity is arranged between the microphone and the membrane.

15. A microphone device comprising: a housing with a sidewall; and a microphone arranged within the housing; and a membrane positioned at an outer surface of the sidewall, wherein a first part of the sidewall has a first thickness, and wherein the membrane includes a second part of the sidewall having a second thickness that is smaller than the first thickness.

16. The microphone device of claim 15 further comprising a cavity arranged between the membrane and the microphone, wherein the second part of the sidewall is arranged adjacent to the cavity, or wherein the cavity is arranged within the sidewall.

17. The microphone device of claim 16, wherein the membrane covers the cavity.

18. The microphone device of claim 16 further comprising at least one support element, wherein the at least one support element retains the microphone at a fixed position relative to at least one of the housing or the sidewall of the housing.

19. The microphone device of claim 18, wherein the cavity is confined by the sidewall of the closed housing, or wherein the cavity is confined by the second part of the sidewall of the housing, and the at least one support element.

20. The microphone device of claim 18, wherein the at least one support element seals the cavity against an inner space of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The features, objects, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference numerals refer to similar elements.

[0024] FIG. 1 depicts a schematic of a first microphone device according to an embodiment;

[0025] FIG. 2 depicts a schematic of a sound wave transmission through the first microphone device according to an embodiment;

[0026] FIG. 3 depicts a schematic of a second microphone device according to another embodiment;

[0027] FIG. 4 depicts a flow chart of a method for generating a microphone device.

DETAILED DESCRIPTION

[0028] FIG. 1 depicts a schematic of a first microphone device. The microphone device 100 comprises a closed housing 102 with a sidewall 104 and a microphone 106 arranged within the closed housing 102. The microphone 106 may be a Micro-Electro-Mechanical-System (MEMS) microphone. At the outer of surface of the sidewall 104, a membrane 108 is situated. A cavity 110 is located between the membrane 108 and the microphone 106. The cavity 110 is located within the sidewall 104 of the closed housing 102. The distance between the cavity 110 and the microphone 106 may be below 2 mm, for example 1.6 mm. The cavity 110 may be filled with air. A first part 112 of the sidewall 104 has a first thickness. The first thickness may be in the range of 1-2 millimeters. The membrane 108 may be comprised by, or in particular formed by, a second part 114 of the sidewall 104. The second part 114 of the sidewall 104 may have a thickness below 1 mm, in particular between 0.2 mm and 0.8 mm, more particularly of 0.4 mm. The second part 114 of the sidewall 104 covers the cavity 110 within the housing 102. The second part 114 may have a lateral size between 0.5 cm and 1.5 cm, in particular a diameter or side length of 10 mm or 12 mm. The second part 114 forming the membrane 108 and sidewall 104 may be made of the same material, for example, one of a polymeric material, metallic material, steel, glass or a composite material.

[0029] The microphone device 100 further comprises two support elements 116, 118. The first support element 118 retains the microphone 106 at a fix position relative to the housing 102. The first support element 118 may comprise a printed circuit board, PCB, which covers the microphone and forms spaces for other devices, such as MEMS devices. The first support element 118 comprise a port hole 122 forming a channel between the cavity 110 and the microphone 106. The microphone device 100 comprises a second support element 116. The second support element 116 confines the cavity 110 between the membrane 108 and the microphone 106 or between the membrane 108 and the first support element 118. The second support element 116 seals the cavity 110 against an inner space 120 of the housing 102. The second support element 116 is partially embedded within the sidewall 104 of the housing 102, more particularly within the cavity 110. The cavity 110 may have a conical or cylindrical shape. The second support element 116 enclosing the cavity 110 may be of plastic or elastomer or another polymeric material.

[0030] FIG. 2 depicts a schematic 200 of the working principle of the microphone device 100. An outer sound wave 202 hits the membrane 108 of the sidewall. FIG. 2 is depicted further in reference to FIG. 1. The sound wave is then transmitted via the membrane 108 into the cavity 110. This inner sound wave 204 may then enter the microphone 106. The shape of the support elements 116 and 118 and the material of the support elements 116 and 118 may determine the frequency response within the cavity 110.

[0031] FIG. 3 depicts a second microphone device 300 according to another embodiment. Aspects of FIG. 3 include one or more features as set forth in connection with FIG. 1. According to this embodiment, the sidewall 104 of the housing includes an opening 304. This opening 304 is adjacent to the cavity 110 within the housing. The opening 304 in the sidewall 104 is covered by an external membrane 302. The opening 304 in the sidewall may be circular or rectangular. The opening 304 may have a lateral size between 0.5 cm and 1.5 cm, in particular a diameter or side length of 10 mm or 12 mm. The membrane 302 may be comprised by a different material than the sidewall of the housing. The membrane 302 may have a thickness below 1 mm, in particular between 0.2 mm and 0.8 mm. The membrane 302 may be made of a polymeric material, metallic material, steel, glass or a composite material. The membrane 302 may be applied sealed to the sidewall 104. For example, the membrane 302 may be adhered to the sidewall 104 or applied by injection molding.

[0032] According to another embodiment, the microphone device 100, 300 may comprise a plurality of microphones 106 arranged as a microphone array. Each of the microphones 108 of the microphone array may be opposed by a respective one of a plurality of membranes 108 and a respect of one of a plurality of cavities 110.

[0033] FIG. 4 depicts the flow diagram of a method for generating the microphone device 100 of any of the above embodiments. The method comprises providing a closed housing 102 within the sidewall 104 in step 402, forming a cavity 110 within the sidewall 104 of the housing 102 in step 404, providing a membrane 108, 302 at an outer surface of the sidewall 104 in step 406 and placing a microphone 106 within the housing at step 408. The cavity 110 is arranged between the microphone 106 and the membrane 108.

[0034] REFERENCE SIGNS

[0035] 100 First microphone device according to an embodiment

[0036] 102 Closed housing

[0037] 104 Sidewall of the housing

[0038] 106 Microphone

[0039] 108 First membrane

[0040] 110 Cavity

[0041] 112 First part of the sidewall

[0042] 114 Second part of the sidewall

[0043] 116 First support element

[0044] 118 Second support element

[0045] 120 Inner space of the housing

[0046] 122 Opening in the second support element

[0047] 200 Schematic of the sound wave transmission through a microphone device

[0048] 202 Sound wave outside the housing

[0049] 204 Sound wave inside the cavity

[0050] 300 Second microphone device according to another embodiment

[0051] 302 Second membrane

[0052] 304 Opening in the sidewall

[0053] 400 Method for generating a microphone device

[0054] 402-408 Steps of the method 400