Packaging concept to improve performance of a micro-electro mechanical (mems) microphone

Patent metadata

Field	Value
Publication number	US-2016014530-A1
Application number	US-201414330788-A
Country	US
Kind code	A1
Filing date	Jul 14, 2014
Priority date	Jul 14, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

A size of a port hole in a package for a micro-electro-mechanical (MEMS) microphone can be modified to improve performance of the MEMS microphone while protecting the MEMS microphone from environmental interference. As an example, the port hole diameter is increased along a thickness of a substrate coupled to the MEMS microphone to reduce air mass loading and air flow resistance and thus, increase the resonant frequency, resonant peak, signal-to-noise ratio (SNR) and/or a range for flat frequency response of the MEMS microphone. In one aspect, the port hole can be created by mechanical and/or laser drilling. In another aspect, the port hole can be created by forming a cavity in the substrate over a drilled port hole.

First claim

1 . A device, comprising:
a micro-electro-mechanical (MEMS) microphone device; and a substrate, coupled to the MEMS microphone device, having a top surface and a bottom surface, wherein the MEMS microphone device is coupled to the top surface, the substrate comprises a port hole that has a first diameter at a first position closer to the top surface and a second diameter at a second position closer to the bottom surface, and wherein the first diameter is larger than the second diameter.

2 . The device of claim 1 , wherein the second diameter is determined based on a design of a motherboard to which the device is to be attached.

3 . The device of claim 1 , wherein the first position is on the bottom surface of the substrate and the second position is on a top surface of the substrate.

4 . (canceled)

5 . The device of claim 1 , wherein the MEMS microphone device is aligned with the port hole.

6 . The device of claim 1 , wherein the MEMS microphone device is not aligned with the port hole.

7 . The device of claim 1 , wherein the MEMS microphone device is coupled to the substrate via a wire bond.

8 . The device of claim 1 , wherein the MEMS microphone device has a flip chip configuration and is electrically coupled to the substrate.

9 . The device of claim 1 , wherein the MEMS microphone device is located on and coupled to an application-specific integrated circuit (ASIC) that is coupled to the substrate.

10 . The device of claim 9 , wherein the MEMS microphone device is coupled to the ASIC via at least one of a wire bond or a eutectic bond.

11 . The device of claim 1 , wherein the MEMS microphone device is coupled to an application-specific integrated circuit (ASIC) and wherein the MEMS microphone device and the ASIC are located on and coupled to the substrate.

12 . The device of claim 1 , wherein the port hole comprises an aperture formed by at least one of mechanically drilling or laser drilling the substrate.

13 . The device of claim 1 , wherein the port hole comprises at least one of a pre-molded or drilled cavity formed in the substrate.

14 . The device of claim 1 , wherein the substrate comprises at least one of a printed circuit board, ceramic, molded package, laminate, or leadframe.

15 . A method, comprising:
coupling a micro-electro-mechanical (MEMS) microphone device to a top surface of a substrate; and forming a port hole within the substrate, wherein the port hole has a first diameter at a first position that is closer to the top surface than a second diameter at a second position of the substrate and wherein the first diameter is larger than the second diameter.

16 . The method of claim 15 , wherein the forming comprises at least one of mechanically drilling or laser drilling the port hole in the substrate.

17 . The method of claim 15 , wherein the forming comprises creating a cavity in the substrate.

18 . (canceled)

19 . The method of claim 15 , further comprising:
customizing the second diameter based on specification data associated with a device to which the MEMS microphone device is to be coupled.

20 . The method of claim 15 , wherein the forming comprises forming the port hole having the first diameter on the bottom surface and the second diameter on the top surface.

21 . The method of claim 15 , wherein the forming comprises forming the port hole during a fabrication process associated with the substrate.

22 . The method of claim 15 , wherein the coupling comprises wire-bonding the MEMS microphone device to the substrate.

23 . The method of claim 15 , wherein the MEMS microphone device has a flip chip configuration and the coupling comprises electrically coupling the MEMS microphone device to the substrate.

24 . The method of claim 15 , wherein the coupling comprises coupling the MEMS microphone device to the substrate via an application-specific integrated circuit (ASIC) that is placed between the MEMS microphone device and the substrate.

25 . The method of claim 15 , further comprising:
coupling an application-specific integrated circuit (ASIC) to the substrate, wherein the ASIC is placed between the MEMS microphone device and the substrate.

26 . A micro-electro-mechanical (MEMS) microphone, comprising:
a MEMS device that facilitates a conversion of an acoustic signal into an electrical signal, wherein the MEMS device is coupled to a top surface of a substrate; and an aperture within the substrate, though which the acoustic signal is received, wherein the aperture has a first diameter at a first position that is closer to the top surface than a second diameter at a second position that is further away from the top surface and wherein the first diameter is larger than the second diameter.

Assignees

• Invensense Inc

Inventors

• Gao Jia

Classifications

• H10W90/753

  between laterally-adjacent chips · CPC title

• H10W90/752

  between stacked chips · CPC title

• H10W90/724

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W70/681

  comprising holes not having chips therein, e.g. for outgassing, underfilling or bond wire passage · CPC title