Sensor device with ingress protection

• US 10,291,973 B2
• Filed: 11/14/2017
• Issued: 05/14/2019
• Est. Priority Date: 05/14/2015
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Lim, Tony K., Talag, Norman Dennis
• Primary Examiner(s): Gauthier, Gerald
• Application Number:
  US15/813,103
• Publication Number:
  US 20180070162A1
• Time in Patent Office: 546 Days
• Field of Search: 257415, 257416, 257704, 257724, 257678, 257680, 348 1402, 381 92, 381174, 381337, 381360, 381361, 381 26, 381 91, 381111, 381162, 381173, 381354, 381355, 381365, 381369, 381175, 607 60, 398133, 438 51, 438125, 2057775
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2201/10 Microfilters, e.g. for gas or fluids
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 7/0029 Protection against environmental influences not provided for in groups B81B7/0012 - B81B7/0025
• CPC Class Codes: B81C 1/00309 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/04 characterised by the shape of the container or parts, e.g. caps, walls
• CPC Class Codes: H01L 23/043 the container being a hollow construction and having a conductive base as a mounting as well as a lead for the semiconductor body
• CPC Class Codes: H01L 24/00 Arrangements for connecting or disconnecting semiconductor or solid-state bodies; Methods or apparatus related thereto
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/16151 Cap comprising an aperture, e.g. for pressure control, encapsulation
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H04R 1/04 : Structural association of microphone with electric circuitry therefor in deaf-aid sets H04R25/00
• CPC Class Codes: H04R 1/086 : Protective screens, e.g. all weather or wind screens
• CPC Class Codes: H04R 19/005 : using semiconductor materials
• CPC Class Codes: H04R 19/04 : Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2499/11 : Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 31/00 : Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182

Abstract

A microphone includes a base and a microelectromechanical system (MEMS) die and an integrated circuit (IC) disposed on the base. The microphone also includes a cover mounted on the base and covering the MEMS die and the IC. The cover includes an indented region or an inwardly drawn region that define a top port through which acoustic energy can enter the microphone and be incident on the MEMS die. The microphone also includes a filtering material disposed on the top port on an outside surface of the cover and within the indented region or the inwardly drawn region. The filtering material provides resistance to ingression of solid particles or liquids into the microphone.

Claims

1. A sensor comprising:

a base having a first surface and an opposing second surface;

a microelectromechanical system (MEMS) die mounted to the first surface of the base;

an integrated circuit (IC) disposed on the base;

a cover disposed over the first surface of the base covering the MEMS die and the IC, the cover having an outer surface and an inner surface, the outer surface of the cover defining an indented region having an indented surface, the cover defining a top port extending between the indented surface and the inner surface, wherein a distance between the indented surface and the inner surface of the cover is less than a distance between the outer surface of the cover and the inner surface of the cover; and

a filtering material disposed on the indented surface covering the top port, the filtering material structured to prevent ingress of contaminants through the top port.

2. The sensor of claim 1, wherein a depth of the indented region is greater than a thickness of the filtering material.

3. The sensor of claim 1, wherein a depth of the indented region is substantially equal to a thickness of the filtering material such that an outer surface of the filtering material is substantially coplanar with the outer surface of the cover.

4. The sensor of claim 1, wherein the filtering material includes a mesh filter.

5. The sensor of claim 1, wherein the base defines a cavity disposed between the first surface and the second surface of the base and an opening disposed under the MEMS die, the opening extending between the cavity and the first surface of the base.

6. The sensor of claim 1, wherein the integrated circuit is mounted on the first surface of the base.

7. The sensor of claim 1, wherein at least a portion of the integrated circuit is embedded into the base.

8. The sensor of claim 1, wherein the sensor is at least one of a microphone, a pressure sensor, or an acoustic sensor.

9. The sensor of claim 1, wherein the filtering material is removably disposed on the indented surface.

10. The sensor of claim 1, wherein the filtering material includes a replaceable mesh filter.

11. A sensor comprising:

a base having a first surface and an opposing second surface;

a microelectromechanical system (MEMS) die mounted to the first surface of the base;

an integrated circuit (IC) disposed on the base;

a cover disposed over the first surface of the base covering the MEMS die and the IC, the cover having an outer surface and an inner surface, the cover further defining an inwardly drawn region forming a depression in the cover, the inwardly drawn region defining a top port, wherein the inwardly drawn region includes a drawn region outer surface and a drawn region inner surface, wherein the top port extends between the drawn region outer surface and the drawn region inner surface; and

a filtering material disposed in the inwardly drawn region and covering the top port, the filtering material structured to prevent ingress of contaminants through the top port.

12. The sensor of claim 11, wherein the inwardly drawn region includes a first sidewall extending between the drawn region inner surface and the inner surface of the cover, and a second sidewall extending between the drawn region outer surface and the outer surface of the cover.

13. The sensor of claim 11, wherein a distance between a plane of the outer surface and a plane of the drawn region outer surface is greater than a thickness of the filtering material.

14. The sensor of claim 11, wherein a distance between a plane of the outer surface and a plane of the drawn region outer surface is substantially equal to a thickness of the filtering material.

15. The sensor of claim 11, wherein the drawn region outer surface defines an indented region having an indented surface, and wherein the top port extends between the indented surface and the drawn region inner surface.

16. The sensor of claim 15, wherein the filtering material is disposed on the indented surface.

17. The sensor of claim 16, wherein the filtering material is removably disposed on the indented surface.

18. The sensor of claim 16, wherein the filtering material includes a replaceable mesh filter.

19. The sensor of claim 16, wherein a distance between a plane of the indented surface and a plane of the outer surface of the cover is greater than a thickness of the filtering material.

20. The sensor of claim 16, wherein a distance between a plane of the indented surface and a plane of the outer surface of the cover is substantially equal to a thickness of the filtering material.

21. The sensor of claim 11, wherein the filtering material is disposed on the drawn region outer surface.

22. The sensor of claim 11, wherein the filtering material includes a mesh filter.

23. The sensor of claim 11, wherein the integrated circuit is mounted on the first surface of the base.

24. The sensor of claim 11, wherein the integrated circuit is embedded into the base.

25. The sensor of claim 11, wherein the base defines a cavity disposed between the first surface and the second surface of the base, and an opening disposed under the MEMS die, the opening extending between the cavity and the first surface of the base.

26. The sensor of claim 11, wherein the sensor is at least one of a microphone, a pressure sensor, or an acoustic sensor.

27. A sensor comprising:

a base having a first surface and an opposing second surface;

a microelectromechanical system (MEMS) die mounted to the first surface of the base;

an integrated circuit (IC) disposed on the base;

a cover disposed over the first surface of the base covering the MEMS die and the IC, the cover having a top surface, the cover further having a bottom surface facing the base, the bottom surface of the cover defining an indented portion having an indented surface, wherein a distance between the indented surface and the top surface of the cover is less than a distance between the bottom surface of the cover and the top surface of the cover, the cover defining a top port within the indented portion; and

a mesh screen disposed within the indented portion and positioned to cover the top port, the mesh screen structured to prevent ingress of particles through the top port.

28. The sensor of claim 27, wherein the mesh screen is flush with the bottom surface.

29. The sensor of claim 27, wherein the indented portion does not extend completely through the cover.

30. The sensor of claim 27, wherein the sensor is at least one of a microphone, a pressure sensor, or an acoustic sensor.