Transducer packaging

Patent metadata

Field	Value
Publication number	US-10696545-B2
Application number	US-201816007799-A
Country	US
Kind code	B2
Filing date	Jun 13, 2018
Priority date	Jun 16, 2017
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

The application describes a package for a MEMS transducer. The package has a package substrate having an acoustic port formed in the package substrate. The acoustic port comprises a first acoustic port volume portion and a second acoustic port volume portion, the first acoustic port volume portion being separated from the second acoustic port volume potion by a discontinuity in a sidewall of the substrate. The cross sectional area of the first acoustic port volume portion is greater than the cross sectional area of the second acoustic port volume portion. A barrier may be attached to the upper surface of the package substrate so as to seal or cover the acoustic port.

First claim

The invention claimed is:

1. A MEMS transducer package having a package substrate, wherein:
an acoustic port extends from a first opening in a first surface of the package substrate to a second opening in a second surface of the package substrate;
a flexible membrane overlies the acoustic port; and
a barrier is provided on or at the first surface at the first opening of the package substrate between the flexible membrane and the acoustic port; wherein the barrier moves in response to a pressure differential across the barrier, and the movement of the barrier causes a corresponding movement of the flexible membrane.

2. A package as claimed in claim 1 , wherein the barrier is supported in relation to the first surface of the package substrate so as to form a seal or cover over the acoustic port.

3. A package as claimed in claim 1 , wherein the first opening is defined by a recess formed in the first surface of the package, the recess forming a first acoustic volume portion.

4. A package as claimed in claim 1 , wherein the cross-sectional area of the opening in the first surface of the package substrate is greater than the cross sectional area of the opening in the second surface of the package substrate.

5. A package for a MEMS transducer as claimed in claim 1 , wherein the shape of one or both of the first and second opening may be one or more of circular, square and rectangular.

6. A package as claimed in claim 1 , wherein the substrate comprises a printed circuit board.

7. A package as claimed in claim 6 , wherein the printed circuit board comprises a multi-layer structure and wherein the first opening in the first surface of the package substrate is formed by a region of one or more upper layers of the printed circuit board where material has been removed.

8. A package as claimed in claim 1 , further comprising a MEMS transducer, wherein the MEMS transducer comprises a flexible membrane.

9. A package as claimed in claim 8 , wherein the MEMS transducer is provided within the package such that the flexible membrane overlies the acoustic port.

10. A package as claimed in claim 1 , wherein the barrier is provided between the flexible membrane and the first surface of the package substrate.

11. A package as claimed in claim 1 , wherein the barrier is formed from a substantially non-porous material.

12. A package as claimed in claim 1 , wherein the barrier comprises one or more of silicone or rubber.

13. A package as claimed in claim 1 , wherein the barrier is supported relative to the upper surface of the package substrate such that the barrier is able to flex in response to pressure variations.

14. A package as claimed in claim 1 , wherein the barrier is adhered to the first surface of the package substrate.

15. A package as claimed in claim 1 , wherein the barrier comprises at least one bleed hole for pressure equalisation.

16. A package as claimed in claim 1 , wherein the barrier substantially inhibits the flow of particles through the barrier.

17. A package as claimed in claim 1 , wherein the barrier is hydrophobic.

18. A package as claimed in claim 1 , wherein the barrier substantially closes the first opening.

19. A package as claimed in claim 1 , wherein the package further comprises a lid.

Assignees

• Cirrus Logic Int Semiconductor Ltd
• Cirrus Logic Inc

Inventors

• KHENKIN Aleksey Sergeyevich
• Patten David

Classifications

• H04R19/04 Primary

  Microphones (H04R19/01 takes precedence) · CPC title

• B81B7/0061

  suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound · CPC title

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title

• B81B3/0021

  Transducers for transforming electrical into mechanical energy or vice versa (dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00) · CPC title

• B81B2207/096

  through the substrate · CPC title