Reduced footprint microphone system with spacer member having through-hole

• US 9,215,519 B2
• Filed: 07/30/2010
• Issued: 12/15/2015
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Goida, Thomas
• Primary Examiner(s): Goins, Davetta W
• Assistant Examiner(s): ETESAM, AMIR HOSSEIN
• Application Number:
  US12/847,682
• Publication Number:
  US 20120027234A1
• Time in Patent Office: 1,964 Days
• Field of Search: 381/150, 381/360, 381/423
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/1461 MEMS
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H04R 1/04 Structural association of microphone with electric circuitry therefor in deaf-aid sets H04R25/00
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 31/006 Interconnection of transducer parts of diaphragm and outer suspension by moulding H04R31/003

Abstract

A microphone system has a chip system coupled to a base. Among other things, the chip system includes a microphone chip and a circuit chip, in a stacked relationship, configured to electrically communicate. The microphone chip has a diaphragm configured to move upon receipt of an incident audio signal, while the circuit chip has at least one through hole audibly coupled with the diaphragm of the microphone chip.

Claims

1. A microphone system comprising:

a base;

a chip system coupled to the base, the chip system comprising a microphone chip and a circuit chip in a stacked relationship, the circuit chip having a body, the circuit chip and microphone chip being configured to electrically communicate,

the microphone chip having a diaphragm configured to move, relative to the backplate, upon receipt of an incident audio signal, the backplate having a plurality of backplate holes, the circuit chip having at least one through hole directly through the circuit chip body forming at least a part of the audio channel to permit audio signals to contact the diaphragm therefore audibly coupled with the diaphragm of the microphone;

a filtering material covering the through hole; and

a nonconductive epoxy film formed about the periphery of the at least one through hole of the circuit chip, securing the microphone chip to the circuit chip and having a plurality of holes that effectively form another filter for and inside the audio channel,

the through hole having a top opening on one side of the circuit chip, the through hole having a bottom opening on the opposite side of the circuit chip, the top opening and the bottom opening having substantially identical dimensions.

2. The microphone system as defined by claim 1 wherein the circuit chip is secured to a surface of the base and the microphone chip is secured to a surface of the circuit chip, the circuit chip being positioned between the microphone chip and the base.

3. The microphone system as defined by claim 1 wherein the through hole comprises a plurality of holes that act as a second filter.

4. The microphone system as defined by claim 1 wherein the base forms an aperture audibly coupled with the through hole in the circuit chip.

5. The microphone system as defined by claim 4 wherein the chip system covers the aperture.

6. The microphone system as defined by claim 1 further comprising a lid that forms an interior with the base, the assembly being within the interior, the lid forming an aperture audibly coupled with the through hole in the circuit chip.

7. The microphone system as defined by claim 6 wherein the through hole forms a back volume for the microphone chip.

19. The microphone as defined by claim 1 wherein the microphone die comprises a variable capacitor and a backside cavity, the chip system being configured so that the backside cavity is between the variable capacitor and the circuit chip.

20. The microphone system as defined by claim 1 wherein the base has an aperture and the filtering material is integrated into the base aperture.

21. The microphone system as defined by claim 1 wherein the filtering material is an insert in the base.

22. The microphone system as defined by claim 1 wherein the base has an aperture coupled to the through hole.

23. The microphone system as defined by claim 1 wherein the base has an aperture that is horizontally spaced from the through hole.

24. The microphone system as defined by claim 1 further including a lid coupled to the base and wherein the circuit chip is coupled to lid such that the through hole is positioned over the lid.

25. The microphone system as defined by claim 24, wherein the base has an aperture.

26. The microphone system as defined by claim 1 wherein the filtering material is in the base aperture.

27. The microphone system as defined by claim 26 wherein the filtering material is an insert.

28. The microphone system as defined by claim 1 wherein the circuit chip body includes active circuitry positioned generally about the general periphery of the circuit chip body.

29. The microphone system as defined by claim 1 wherein the circuit chip body includes active circuitry positioned generally about a portion of the periphery of the circuit chip.

35. The microphone system as defined by claim 1 wherein the holes of the nonconductive epoxy film are sized and positioned relative to the holes of the backplate to maximize the filtering capability of the nonconductive epoxy film.

8. A microphone system comprising:

a base;

a lid coupled to the base to form a package with an interior and an inner surface;

an aperture formed though the package;

a chip system secured to the inner surface, the chip system including a circuit chip and MEMS microphone chip coupled in a stacked relationship, the circuit chip have a body,

the circuit chip and MEMS microphone chip being configured to electrically communicate,

the MEMS microphone chip having a diaphragm configured to move, relative to a backplate, upon receipt of an incident audio signal, the backplate having a plurality of backplate holes,

the circuit chip having at least one through hole directly through the circuit chip body forming at least a part of the audio channel to permit audio signals to contact the diaphragm therefore audibly coupled with the diaphragm of the microphone;

a filtering material covering the through hole; and

a nonconductive epoxy film formed about the periphery of the at least one through hole of the circuit chip, securing the microphone chip to the circuit chip and having a plurality of holes that effectively form another filter for and inside the audio channel,

the through hole having a top opening on one side of the circuit chip, the through hole having a bottom opening on the opposite side of the circuit chip, the top opening and the bottom opening having substantially identical dimensions.

9. The system as defined by claim 8 wherein the base forms the aperture, the chip system secured to the base covering the aperture, the circuit chip being between the MEMS microphone chip and the base.

10. The system as defined by claim 8 wherein the lid forms the aperture, the through hole forming a back volume for the MEMS microphone chip.

11. The system as defined by claim 8 further comprising a second filter between the aperture and the diaphragm.

12. The system as defined by claim 11 wherein the second filter covers one of the aperture and the through hole.

13. The system as defined by claim 11 wherein the second filter is coupled between the MEMS microphone chip and the circuit chip.

14. The system as defined by claim 8 wherein the base comprises circuit board material and the lid comprises a conductor.

30. The microphone system as defined by claim 8 wherein the circuit chip body includes active circuitry positioned generally about the general periphery of the circuit chip.

31. The microphone system as defined by claim 8 wherein the circuit chip body includes active circuitry positioned generally about a portion of the periphery of the circuit chip.

36. The microphone system as defined by claim 8 wherein the holes of the nonconductive epoxy film are sized and positioned relative to the holes of the backplate to maximize the filtering capability of the nonconductive epoxy film.

15. A microphone system comprising:

a package having a base and forming an interior;

a chip system coupled to the base within the package interior, the chip system comprising a MEMS microphone and a member in a stacked relationship, the member having a body,

the MEMS microphone having a diaphragm configured to move, relative to a backplate, upon receipt of an incident audio signal, the member having at least one through hole directly through the member body forming at least a part of an audio channel to permit audio signals to contact the diaphragm therefore audibly coupled with the diaphragm of the MEMS microphone, the backplate having a plurality of backplate holes; and

a filtering material covering the through hole; and

a nonconductive epoxy film formed about the periphery of the at least one through hole of the circuit chip, securing the microphone chip to the circuit chip and having a plurality of holes that effectively form another filter for and inside the audio channel,

the through hole having a top opening on one side of the member, the through hole having a bottom opening on the opposite side of the member, the top opening and the bottom opening having substantially identical dimensions.

16. The microphone as defined by claim 15 wherein the member comprises a circuit chip in electrical communication with the MEMS microphone.

17. The microphone as defined by claim 15 wherein the member comprises an inactive silicon member.

18. The microphone as defined by claim 15 wherein the base comprises an aperture, the member being coupled to the base and covering the aperture.

32. The microphone system as defined by claim 15 wherein the member body includes active circuitry positioned generally about the general periphery of the member.

33. The microphone system as defined by claim 15 wherein the member body includes active circuitry positioned generally about a portion of the periphery of the member.

34. The microphone system as defined by claim 15 wherein the member includes a seal between the member and the MEMS microphone to acoustically seal the through hole to the MEMS microphone to form a portion of the audio channel, further wherein the seal is positioned in between and in direct contact with the member and the microphone chip and the circuit chip has holes and the seal includes holes and the seal holes, the backplate holes and the holes in the circuit chip are aligned.

37. The microphone system as defined by claim 15 wherein the holes of the nonconductive epoxy film are sized and positioned relative to the holes of the backplate to maximize the filtering capability of the nonconductive epoxy film.