TOP PORT MULTI-PART SURFACE MOUNT SILICON CONDENSER MICROPHONE

• US 20170264997A1
• Filed: 05/26/2017
• Published: 09/14/2017
• Est. Priority Date: 11/28/2000
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Minervini, Anthony D.
• Granted Patent: US 9,980,038 B2
• Time in Patent Office: Days
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2207/092 Buried interconnects in the substrate or in the lid
• CPC Class Codes: B81B 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81B 7/0058 for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
• CPC Class Codes: B81B 7/0061 suitable for fluid transfer from the MEMS out of the package or vice versa, e.g. transfer of liquid, gas, sound
• CPC Class Codes: B81B 7/0064 for protecting against electromagnetic or electrostatic interferences
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: B81C 3/00 Assembling of devices or systems from individually processed components
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/15 Ceramic or glass substrates H01L23/142, H01L23/145, H01L23/147 take precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H04R 1/04 Structural association of microphone with electric circuitry therefor in deaf-aid sets H04R25/00
• CPC Class Codes: H04R 1/222 for microphones H04R1/24, H04R1/26 take precedence
• CPC Class Codes: H04R 1/2892 Mountings or supports for transducers
• CPC Class Codes: H04R 19/005 : using semiconductor materials
• CPC Class Codes: H04R 19/016 : for microphones
• CPC Class Codes: H04R 19/04 : Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 : Mems transducers or their use
• CPC Class Codes: H04R 2225/49 : Reducing the effects of electromagnetic noise on the functioning of hearing aids, by, e.g. shielding, signal processing adaptation, selective (de)activation of electronic parts in hearing aid
• CPC Class Codes: H04R 23/00 : Transducers other than those covered by groups H04R9/00 - H04R21/00 diaphragms for transducers of the distributed-mode type H04R7/045
• CPC Class Codes: H04R 2410/03 : Reduction of intrinsic noise in microphones
• CPC Class Codes: H04R 3/00 : Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: H04R 31/006 : Interconnection of transducer parts of diaphragm and outer suspension by moulding H04R31/003
• CPC Class Codes: Y10T 29/49005 : Acoustic transducer
• CPC Class Codes: Y10T 29/4908 : Acoustic transducer
• CPC Class Codes: Y10T 29/49798 : Dividing sequentially from leading end, e.g., by cutting or breaking

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.

Claims

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 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,

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.

12. The MEMS microphone of claim 11, wherein the means for electrically interfacing further comprises an acoustic material that substantially blocks contaminants from passing through the acoustic port.

13. The MEMS microphone of claim 12, wherein the acoustic material to block environmental contaminants is a film of polymeric material.

14. The MEMS microphone of claim 12, wherein the acoustic material to block environmental contaminants is hydrophobic.

15. The MEMS microphone of claim 11, wherein the MEMS microphone die is a pressure-equalizing MEMS microphone die, 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 means for electrically interfacing of the substrate is acoustically coupled to the front volume.

16. The MEMS microphone of claim 15, wherein the interface between the attachment surface of the sidewall portion of the cover and the peripheral region of the top surface of the means for electrically interfacing is sealed to maintain acoustic pressure within the back volume.

17. The MEMS microphone of claim 11, 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.

18. The MEMS microphone of claim 17, 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.

19. The MEMS microphone of claim 17, 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.

20. The MEMS microphone of claim 17, 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.