Top port multi-part surface mount silicon condenser microphone

Patent metadata

Field	Value
Publication number	US-9980038-B2
Application number	US-201715606686-A
Country	US
Kind code	B2
Filing date	May 26, 2017
Priority date	Nov 28, 2000
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A surface mount package for a micro-electro-mechanical system (MEMS) microphone die is disclosed. The surface mount package features a substrate with metal pads for surface mounting the package to a device's printed circuit board and for making electrical connections between the microphone package and the device's circuit board. The surface mount microphone package has a cover, and the MEMS microphone die is substrate-mounted and acoustically coupled to an acoustic port provided in the surface mount package. The substrate and the cover are joined together to form the MEMS microphone, and the substrate and cover cooperate to form an acoustic chamber for the substrate-mounted MEMS microphone die.

First claim

What is claimed is:

1. A silicon condenser microphone comprising:
means for electrically interfacing to a printed circuit board comprising:
a top layer comprising a first conductive layer with a first non-conductive layer disposed on a lower surface of the first conductive layer, wherein the first conductive layer is patterned to form a plurality of conductive pads;
a bottom layer comprising a second non-conductive layer with a second conductive layer disposed on a lower surface of the second non-conductive layer, wherein the second conductive layer is pattered to form a plurality of flat solder pads, wherein the top and bottom layers are in facing relation to each other; and
one or more electrical paths disposed completely within the means for electrically interfacing, wherein the one or more electrical paths electrically couple one or more of the plurality of conductive pads in the first conductive layer to one or more of the solder pads in the second conductive layer,
wherein the means for electrically interfacing is rigid, is adapted for solder reflow surface mounting, and has substantially planar top and bottom surfaces;

a micro-electro-mechanical system (MEMS) microphone die mounted to the top surface of the means for electrically interfacing and electrically coupled to at least one of the conductive pads in the first conductive layer; and
a single-piece environmental protection means that includes an acoustic port,
wherein the environmental protection means is formed from a solid material and has a predetermined shape with a rectangular top portion and a substantially vertical and continuous sidewall portion that adjoins the top portion at an angle and that completely surrounds and supports the top portion, the sidewall portion having a predetermined height, an exterior sidewall surface, an interior sidewall surface, and an attachment surface, the acoustic port disposed in the top portion of the environmental protection means and passing completely through the environmental protection means,
wherein the attachment surface of the sidewall portion of the environmental protection means is aligned with and attached to a peripheral region along each edge of the top surface of the means for electrically interfacing, and
wherein the predetermined height of the sidewall portion of the environmental protection means, the interior sidewall surface of the sidewall portion of the environmental protection means, and an interior surface of the top portion of the environmental protection means, in cooperation with the top surface of the means for electrically interfacing, provide a protective enclosure for the MEMS microphone die to reduce electromagnetic interference.

2. The silicon condenser microphone of claim 1 , wherein the means for electrically interfacing further comprises a recess disposed within the means for electrically interfacing, and the MEMS microphone die is positioned over the recess.

3. The silicon condenser microphone of claim 1 , wherein the means for electrically interfacing further comprises an internal cavity with an aperture in the top surface of the means for electrically interfacing, the internal cavity extending longitudinally within the means for electrically interfacing, and the MEMS microphone die is positioned over the aperture in the top surface of the means for electrically interfacing.

4. The silicon condenser microphone of claim 1 , wherein the MEMS microphone die is a pressure-equalizing MEMS microphone die, and wherein a diaphragm of the MEMS microphone die defines a front volume and a back volume within the protective enclosure, and the acoustic port disposed in the environmental protection means is acoustically coupled to the diaphragm.

5. The silicon condenser microphone of claim 4 , wherein the interface between the attachment surface of the sidewall portion of the environmental protection means and the top surface of the means for electrically interfacing is sealed to maintain acoustic pressure within the front volume.

6. The silicon condenser microphone of claim 1 , wherein the first and second non-conductive layers comprise one or more layers of FR-4 printed circuit board material.

7. The silicon condenser microphone of claim 1 , wherein the means for electrically interfacing further comprises:
a third conductive layer disposed on a lower surface of the first non-conductive layer;
a fourth conductive layer disposed on a upper surface of the second non-conductive layer, wherein the third and fourth conductive layers are patterned into electrodes;
a passive electronic material layer disposed between the third and fourth conductive layers and in electrical contact with the third and fourth conductive layers.

8. The silicon condenser microphone of claim 7 , wherein the passive electronic material layer is a resistive material, and is electrically coupled to one or more of the plurality of conductive pads in the first conductive layer or one or more of the solder pads in the second conductive layer through one or more of the electrodes formed in the third and fourth conductive layers.

9. The silicon condenser microphone of claim 7 , wherein the passive electronic material layer is a capacitive dielectric material, and is electrically coupled to one or more of the plurality of conductive pads in the first conductive layer or one or more of the solder pads in the second conductive layer through one or more of the electrodes formed in the third and fourth conductive layers.

10. The silicon condenser microphone of claim 7 , wherein a passive electrical element formed in the passive electronic material layer filters one or more of an input signal, an output signal, or input power.

11. A micro-electro-mechanical system (MEMS) microphone, the microphone comprising:
means for electrically interfacing to a printed circuit board comprising:
a top layer comprising a first conductive layer with a first non-conductive layer disposed on a lower surface of the first conductive layer, wherein the first conductive layer is patterned to form a plurality of conductive pads;
a bottom layer comprising a second non-conductive layer with a second conductive layer disposed on a lower surface of the second non-conductive layer, wherein the second conductive layer is pattered to form a plurality of flat solder pads, the top and bottom layers in facing relation to each other;
one or more electrical paths disposed completely within the means for electrically interfacing, wherein the one or more electrical paths electrically couple one or more of the plurality of conductive pads in the first conductive layer to one or more of the solder pads in the second conductive layer; and
an acoustic port disposed in an interior region of the means for electrically interfacing and passing completely through the means for electrically interfacing, wherein one of the plurality of flat solder pads in the second conductive layer is a metal ring that completely surrounds the acoustic port in the means for electrically interfacing,

wherein the means for electrically interfacing is rigid, is adapted for solder reflow surface mounting, and has substantially planar top and bottom surfaces;

a micro-electro-mechanical system (MEMS) microphone die mounted to the top surface of the means for electrically interfacing and electrically coupled to at least one of the conductive pads in the first conductive layer, the MEMS microphone die being disposed directly over the acoustic port in the means for electrically interfacing; and
a single-piece environmental protection means,
wherein the environmental protection means is formed from a solid material and has a predetermined shape with a rectangular top portion

Assignees

• Knowles Electronics Llc

Inventors

• Minervini Anthony D

Classifications

• H10P54/00

  Cutting or separating of wafers, substrates or parts of devices · CPC title

• H10W76/60

  Seals · CPC title

• H10W70/692

  Ceramics or glasses · CPC title

• H04R1/222

  for microphones (H04R1/24, H04R1/26 take precedence) · CPC title

• H04R1/04

  Structural association of microphone with electric circuitry therefor (in electric hearing aids H04R25/00) · CPC title