Microphone assembly

Abstract

The invention relates to a microphone assembly, especially for external use for a vehicle, comprising: - a housing base comprising at least one compartment; - a PCBA (Printed Circuit Board Assembly) with at least one acoustic membrane; - a sealing cover at least partially overlapping the compartment; - wherein the sealing cover comprises at least one opening at least partially aligned with the acoustic membrane; - further comprising a housing cover; - wherein the housing cover comprises a first grid at least partially aligned with the opening in the sealing cover; - and a shielding cover; - wherein the shielding cover comprises a second grid at least partially aligned with the opening in the sealing cover; wherein the first grid and the second grid are offset aligned in order to provide a labyrinth path without a straight through passage from the outside of the microphone assembly to the acoustic membrane.

Description

TECHNICAL FIELD

[0001] The present invention relates to a microphone assembly, mainly for use in a car. BACKGROUND

[0002] Common interior microphone assemblies cannot be used outside of a vehicle, as environmental impacts cause malfunction or damage of the microphone assembly.

[0003] Especially, the influence of moisture and water often causes defects.

[0004] It is an object of the present invention to provide a microphone assembly that can be used outside of a vehicle, and, most preferred embodiments, comply with high IP protection, such as IP6k9k. SUMMARY

[0005] This object is achieved by a microphone assembly, especially a microphone assembly for use outside of a vehicle, comprising:

[0006] - a housing base comprising at least one compartment,

[0007] - a PCBA (Printed Circuit Board Assembly) with at least one acoustic membrane,

[0008] - a sealing cover to at least partially overlap the compartment,

[0009] - wherein the sealing cover comprises at least one opening, said opening at least partially aligned with said acoustic membrane,

[0010] - further comprising a housing cover,

[0011] - wherein the housing cover comprises a first grid, said first grid at least partially aligned with said opening in the sealing cover,

[0012] - and a shielding cover,

[0013] - wherein the shielding cover comprises a second grid, said second grid at least partially aligned with said opening in the sealing cover,

[0014] - wherein the first grid and the second grid are offset aligned so as to provide a labyrinthine path, which has no straight-through passage from the outside of the microphone assembly to the acoustic membrane.

[0015] By providing a water-tight around the acoustic membrane and sealing the PCBA from the environment using a sealing cover, and by avoiding direct impact of water on the acoustic membrane via a bias-aligned grid, the microphone assembly can withstand hydrostatic pressure, and pressure impact of water (e.g. by rain or momentum when driving in the rain or under a water jet) can reach the acoustic membrane directly through the grid.

[0016] The features of the preceding claims will be further described by preferred embodiments. The invention is in no way limited to the shown embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] Embodiments are shown in the following drawings.

[0018] Figure 1 is an exploded view of the main parts of the microphone assembly;

[0019] Figure 2a / b is a detail of the housing base (a) and the sealing cover (b);

[0020] Figure 3 is a cross-section through the microphone assembly, showing the interaction of the parts. DETAILED DESCRIPTION

[0021] Figure 1 An exploded view of a microphone assembly 1 according to the invention is shown. The microphone assembly 1 comprises:

[0022] - a housing base 2 comprising at least one compartment 3,

[0023] - a PCBA 4 (Printed Circuit Board Assembly) having at least one acoustic membrane 5,

[0024] - a sealing cover 6 to at least partially overlap the compartment 3,

[0025] - wherein the sealing cover 6 comprises at least one opening 7 at least partially aligned with the acoustic membrane 5,

[0026] - further comprising a housing cover 8,

[0027] - wherein the housing cover 8 comprises a first grid 9 at least partially aligned with the opening 7 in the sealing cover 6,

[0028] - and a shielding cover 10,

[0029] - wherein the shielding cover 10 comprises a second grid 11 at least partially aligned with the opening 7 in the sealing cover 6.

[0030] The compartment 3 of the housing base 2 is formed by a compartment wall 12 that surrounds a defined area for enclosing and supporting the PCBA 4. The upper surface 13 of the compartment wall 12 carries a sealing rib 14. The sealing rib 14 is provided to interact with a groove arrangement 20 on the sealing cover 6, which will be described in detail in Figure 2b

[0031] The PCBA 4 comprises an acoustic membrane 5 configured as a waterproof acoustic membrane 5. The outer periphery 15 of the acoustic membrane 5 is configured to interact with sealing rings 21, 22 and 23, which will be described in detail in Figure 2b

[0032] The sealing cover 6 itself is configured to at least partially receive the compartment wall 12 and to establish a surrounding contact between the inner flank 26 of the sealing cover wall element 16 and the outer flank 27 of the compartment wall 12.

[0033] The sealing cover 6 further forms a rim area 17 that separates a wall portion 18 of the housing cover 8 from a receptacle portion 19 of the housing base 2. By manufacturing the sealing cover 6 with a flexible material, such as silicone rubber, the pressing between the wall portion 18 and the receptacle portion 19 provides a sealing and protects the inner area of the compartment 3 and, by this, the PCBA 4 from external influences, such as water. The stacked arrangement will be described in detail in Figure 3

[0034] Figure 2a and Figure 2b An enlarged sectional view shows the interacting sealing elements. Figure 2a A sectional view of the housing base 2 with the compartment wall 12 and the bolt receptacle 24 is shown.

[0035] Figure 2b A flipped view of the sealing cover 6 is shown. The inner area 25 of the sealing cover 6 will receive the compartment 3 of the PCBA 4. The inner flank 26 of the wall element 16 is aligned with the groove arrangement 20. These groove arrangements 20 interact with the sealing rib 14 on the compartment wall 12 and form a tight sealing. Additionally, as mentioned above, the flanks 26, 27 of the wall element as well as the rim area 17 also provide a sealing function.

[0036] Figure 2b The sealing rings 21, 22 and 23 are also shown, which are arranged coaxially around the opening 7 in the sealing cover 6. The sealing rings 21, 22 and 23 extend radially from the center of the opening 7 to form multiple seals when interacting with the outer periphery 15 as a sealing area on the acoustic membrane 5 on the PCBA 4. By this sealing, external influences, such as water, on the acoustic membrane 5 cannot reach the inner volume of the compartment 3 and harm the electronic components of the PCBA 4. ​​​

[0037] The sealing cover 6 also comprises holes 28 which assist in the alignment of the rim area 17 by receiving the bolt receptacles 24.

[0038] Figure 3 A cross-sectional view through the assembled microphone assembly 1 is shown. The wall elements 12 of the compartment 3 interact with the sealing cover 6 to form a labyrinth-like seal, represented by sealing points 31 in the position of the groove arrangement 20 and the sealing ribs 14. The sealing rings 21, 22 and 23 form a seal against water, for example from the central opening 7, represented by sealing points 32 and 33.

[0039] To avoid significant impact momentum of, for example, splashing water, the first and second grid 9 and 11 are arranged with a coplanar offset 34. For reasons of clarity, only one post is marked per grid. Due to the space 35 in height between the first and second grid 9 and 11, sound waves are able to travel to the acoustic membrane 5 by meandering through the grid. Splashing water, for example from rain or a water jet, is not able to meander through the channels, and furthermore, any impact momentum, for example of water, will be damped by the grids 9 and 11 before hitting the acoustic membrane 5. Due to this effect, the seals 31, 32 and 33 are sufficient to protect the PCBA 4 from the environment and allow the microphone assembly 1 to be used externally, for example in a car or vehicle.

Claims

1. A microphone assembly for external use by a vehicle, comprising: - a housing base comprising at least one compartment, - a printed circuit board assembly having at least one acoustic membrane, - a sealing cover at least partially overlapping said compartment, - wherein said sealing cover comprises at least one opening at least partially aligned with said acoustic membrane, - further comprising a housing cover, - wherein said housing cover comprises a first grid at least partially aligned with said opening in said sealing cover, - and a shielding cover, - wherein said shielding cover comprises a second grid at least partially aligned with said opening in said sealing cover, characterized in that said first grid and said second grid are offsetly aligned so as to provide a labyrinthine path having no straight-through passage from the exterior of said microphone assembly to said acoustic membrane, wherein said sealing cover comprises a rim area separating a wall portion of said housing cover from a seating portion of said housing base.

2. The microphone assembly of claim 1, wherein, said sealing cover comprises at least one sealing ring arranged on said printed circuit board assembly, facing a side of said sealing cover and coaxially aligned with said opening.

3. The microphone assembly of claim 1 or 2, wherein, said acoustic membrane forms a water-proof at least partial cover for said printed circuit board assembly.

4. The microphone assembly of claim 1 or 2, wherein, said sealing cover provides a groove arrangement to interact with a corresponding sealing rib on a wall section of said compartment, said sealing rib providing a circumferential contact between said wall section of said compartment and said groove arrangement of said sealing cover.

5. The microphone assembly of claim 1 or 2, wherein, said sealing cover is at least partially made of silicone rubber.

6. The microphone assembly of claim 2, wherein, said sealing cover comprises a plurality of sealing rings.

7. The microphone assembly of claim 2, wherein, said sealing cover comprises three sealing rings.

8. The microphone assembly of claim 2, wherein, said sealing rings extend radially from a center of said opening.

9. The microphone assembly of claim 5, wherein, said sealing cover is entirely made of silicone rubber.

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