Embedded dielectric as a barrier in an acoustic device and method of manufacture

• US 9,374,643 B2
• Filed: 11/04/2011
• Issued: 06/21/2016
• Est. Priority Date: 11/04/2011
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Szczech, John B., Van Kessel, Peter
• Primary Examiner(s): NGUYEN, TUAN DUC
• Application Number:
  US14/354,020
• Publication Number:
  US 20140294209A1
• Time in Patent Office: 1,691 Days
• US Class Current: 1/1
• CPC Class Codes: B32B 15/085 comprising polyolefins
• CPC Class Codes: B32B 15/16 next to a particulate layer
• CPC Class Codes: B32B 15/20 comprising aluminium or copper B32B15/016 and B32B15/017 take precedence
• CPC Class Codes: B32B 2264/0257 Polyolefin particles, e.g. polyethylene or polypropylene homopolymers or ethylene-propylene copolymers
• CPC Class Codes: B32B 2307/10 having particular acoustical properties
• CPC Class Codes: B32B 2307/204 Di-electric
• CPC Class Codes: B32B 2307/206 Insulating
• CPC Class Codes: B32B 2327/18 PTFE, i.e. polytetrafluoroethylene
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• 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: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2924/15151 the die mounting substrate comprising an aperture, e.g. for underfilling, outgassing, window type wire connections
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• 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 17/025 using a piezoelectric polymer
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2307/025 Diaphragms comprising polymeric materials
• CPC Class Codes: H04R 31/006 Interconnection of transducer parts of diaphragm and outer suspension by moulding H04R31/003
• CPC Class Codes: H04R 7/10 : comprising superposed layers in contact

Abstract

A microphone base includes a plurality of metal layers and a plurality of core layers. Each of the plurality of core layers is disposed between selected ones of the metal layers. A dielectric membrane is disposed between other selected ones of the plurality of metal layers. A port extends through the metal layers and the core layers but not through the dielectric membrane. The dielectric membrane has a compressed portion and an uncompressed portion. The uncompressed portion extends across the port and the compressed portion is in contact with the other selected ones of the metal layers. The compressed portion of the membrane is effective to operate as a passive electronic component and the uncompressed portion is effective to act as a barrier to prevent at least some external debris from traversing through the port.

Claims

1. A microphone base, the base comprising:

a plurality of metal layers;

a plurality of core layers, each of the plurality of core layers being disposed between selected ones of the metal layers;

a dielectric membrane disposed between other selected ones of the plurality of metal layers;

a port that extends through the metal layers and the core layers but not through the dielectric membrane;

such that the dielectric membrane has a compressed portion and an uncompressed portion, the uncompressed portion extending across the port and the compressed portion being in contact with the other selected ones of the metal layers;

such that the compressed portion of the membrane is effective to operate as a passive electronic component and the uncompressed portion is effective to act as a barrier to prevent at least some external debris from traversing through the port.

2. The base of claim 1 wherein the dielectric constant value of the compressed portion is different than the dielectric constant value of the uncompressed portion.

3. The base of claim 1 wherein the membrane comprises an expanded Teflon expanded polytetrafluoroethylene (ePTFE) film.

4. The base of claim 1 wherein the electronic component comprises a capacitor.

5. The base of claim 1 wherein the port has a diameter greater than approximately 1.0 mm.

6. A microphone comprising:

a base, the base comprising;

a plurality of metal layers;

a plurality of core layers, each of the plurality of core layers being disposed between selected ones of the metal layers;

a dielectric membrane disposed between other selected ones of the plurality of metal layers;

a port that extends through the metal layers and the core layers but not through the dielectric membrane;

such that the dielectric membrane has a compressed portion and an uncompressed portion, the uncompressed portion extending across the port and the compressed portion being in contact with the other selected ones of the metal layers;

such that the compressed portion of the membrane is effective to operate as a passive electronic component and the uncompressed portion of the membrane is effective to act as a barrier to prevent at least some external debris from traversing through the port;

a transducer disposed over and coupled to the base and communicating with the port, the transducer configured to covert sound energy received from the port into electrical energy.

7. The microphone of claim 6 further comprising a cover attaching to the base, the cover covering the transducer.

8. The microphone of claim 6 further comprising an amplifier coupled to the transducer.

9. The microphone of claim 6 wherein the dielectric constant value of the compressed portion is different than the dielectric constant value of the uncompressed portion.

10. The microphone of claim 6 wherein the membrane comprises an expanded Teflon expanded polytetrafluoroethylene (ePTFE) film.

11. The microphone of claim 6 wherein the electronic component comprises a capacitor.

12. The microphone of claim 6 wherein the port has a diameter greater than approximately 1.0 mm.