MEMS microphone assembly and method of manufacturing the MEMS microphone assembly

1. MEMS microphone assembly, comprising

a MEMS transducer element comprising a MEMS die, a back plate and a diaphragm displaceable in relation to the back plate, and

a sound inlet for acoustically coupling the MEMS transducer element to the exterior of the MEMS microphone assembly, wherein the MEMS die comprises an indentation that forms at least a part of the sound inlet.

2. MEMS microphone assembly according to claim 1 , further comprising a cover defining a cavity between the diaphragm and the cover.

3. MEMS microphone assembly according to claim 2 , wherein the indentation is placed adjacent to the cavity.

4. MEMS microphone assembly according to claim 3 , wherein the indentation opens out into the cavity.

5. MEMS microphone assembly according to claim 3 , wherein the indentation is tapered such that its width increases towards the cavity.

6. MEMS microphone assembly according to claim 2 , wherein the indentation is tapered such that its width increases towards the cavity.

7. MEMS microphone assembly according to claim 2 ,

further comprising a substrate, wherein the MEMS transducer element is mounted on the substrate and the sound inlet is arranged on a side of the MEMS transducer element facing away from the substrate.

8. MEMS microphone assembly according to claim 2 ,

wherein the MEMS transducer element is covered by a sealing layer and an opening extends through the sealing layer, the opening defining a part of the sound inlet.

9. MEMS microphone assembly according to claim 2 , comprising multiple sound inlets.

10. MEMS microphone assembly according to claim 1 ,

further comprising a substrate, wherein the MEMS transducer element is mounted on the substrate and the sound inlet is arranged on a side of the MEMS transducer element facing away from the substrate.

11. MEMS microphone assembly according to claim 1 ,

wherein the MEMS transducer element is covered by a sealing layer and an opening extends through the sealing layer, the opening defining a part of the sound inlet.

12. MEMS microphone assembly according to claim 1 , comprising multiple sound inlets.

13. MEMS microphone assembly according claim 12 , wherein the MEMS die comprises at least two indentations, each indentation defining at least a part of one of the sound inlets.

14. MEMS microphone assembly according to claim 13 ,

wherein the MEMS transducer element is covered by a sealing layer and multiple openings extend through the sealing layer, each opening being in acoustic contact with at least one indentation.

15. MEMS microphone assembly according to claim 1 , wherein the indentation is configured to lead sound signals sideways into a cavity that forms a front volume of the transducer element.

16. MEMS microphone assembly according to claim 1 , wherein the indentation is defined in the MEMS die.

17. Method of manufacturing a MEMS microphone assembly, comprising the steps of:

providing a substrate,

mounting a MEMS transducer element comprising a MEMS die, a back plate and a diaphragm displaceable in relation to the back plate on the substrate, wherein the MEMS die comprises an indentation,

covering the MEMS transducer element with a sealing layer, and

forming an opening in the sealing layer that is in acoustic contact with the indentation of the MEMS die such that a sound inlet for acoustically coupling the transducer element to the exterior of the MEMS microphone assembly is formed.

18. Method according to claim 17 , wherein the indentation of the MEMS die is formed on wafer-level.

19. Method according to claim 18 ,

wherein the MEMS die comprises multiple indentations and multiple openings are formed in the sealing layer such that each opening is in acoustic contact with at least one indentation and each indentation forms at least a part of a sound inlet for acoustically coupling the MEMS transducer element to the exterior of the MEMS microphone assembly.

20. Method according to claim 18 , wherein the opening is formed by laser cutting.

21. Method according to claim 17 ,

wherein the MEMS die comprises multiple indentations and multiple openings are formed in the sealing layer such that each opening is in acoustic contact with at least one indentation and each indentation forms at least a part of a sound inlet for acoustically coupling the MEMS transducer element to the exterior of the MEMS microphone assembly.

22. Method according to claim 17 , wherein the opening is formed by laser cutting.