Microphone package

• US 10,631,099 B2
• Filed: 09/11/2018
• Issued: 04/21/2020
• Est. Priority Date: 05/25/2017
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Lim, Tony K., Szczech, John, Watson, Joshua
• Primary Examiner(s): Laekemariam, Yosef K
• Application Number:
  US16/128,489
• Publication Number:
  US 20190014421A1
• Time in Patent Office: 588 Days
• Field of Search: 381 26, 381 92, 381113, 381114, 381116, 381111, 381122, 381361
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2207/012 the micromechanical device and the control or processing electronics being separate parts in the same package
• CPC Class Codes: B81B 7/0019 Protection against thermal alteration or destruction B81B7/0083 takes precedence
• CPC Class Codes: B81B 7/0025 Protection against chemical alteration
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• 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 2924/15151 the die mounting substrate comprising an aperture, e.g. for underfilling, outgassing, window type wire connections
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/16151 Cap comprising an aperture, e.g. for pressure control, encapsulation
• 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 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: H04R 3/06 of electrostatic transducers

Abstract

A microphone includes a substrate defining an embedded cavity between a first surface of the substrate and an opposing second surface of the substrate, the first surface defining a first opening into the embedded cavity, a distance between the first surface and the second surface defining a substrate thickness. A cover is disposed over the first surface of the substrate and forms a housing, the cover including a port, the substrate thickness being greater than a height of the cover from the first surface of the substrate. A microelectromechanical systems (MEMS) transducer is disposed in the housing and mounted on the first surface of the substrate over the first opening, and an integrated circuit (IC) is disposed in the housing and electrically coupled to the MEMS transducer. The MEMS transducer and the IC are disposed in a front volume of the housing defined by the cover and the substrate.

Claims

1. A microphone comprising:

a substrate defining an embedded cavity between a first surface of the substrate and an opposing second surface of the substrate, the first surface defining a first opening into the embedded cavity, a distance between the first surface and the second surface defining a substrate thickness;

a cover disposed over the first surface of the substrate and forming a housing, the cover including a port, the substrate thickness being greater than a height of the cover from the first surface of the substrate;

a microelectromechanical systems (MEMS) transducer disposed in the housing and mounted on the first surface of the substrate over the first opening; and

an integrated circuit (IC) disposed in the housing and electrically coupled to the MEMS transducer,

the MEMS transducer and IC disposed in a front volume of the housing, the front volume defined by the cover and the substrate,

wherein the port extends between the front volume and an exterior of the housing.

2. The microphone of claim 1, wherein the cover includes a thin region, a thickness of the thin region less than a thickness of other portions of the cover.

3. The microphone of claim 2, wherein the thin region is positioned adjacent a periphery of the port.

4. The microphone of claim 1, the first surface of the substrate defining a second opening into the embedded cavity.

5. The microphone of claim 4, the second opening positioned under the IC.

6. The microphone of claim 4, the MEMS transducer is a multi-motor transducer, the first opening located under a first diaphragm of the MEMS transducer and the second opening located under a second diaphragm of the MEMS transducer.

7. The microphone of claim 1, further comprising a cover bonding ring disposed on the first surface, the cover bonding ring defining a notch, the cover disposed on the cover bonding ring, and an under-fill adhesive positioned in the notch securing the cover to the substrate.

8. The microphone of claim 1 further comprising a particulate filter covering the first opening.

9. The microphone of claim 1 further comprising a passive electrical circuit element embedded in the substrate.

10. The microphone of claim 9, wherein the passive electrical circuit element is reactive.

11. The microphone of claim 9, wherein the passive electrical circuit element includes a resistor and a capacitor.

12. The microphone of claim 11, wherein the capacitor and resistor are formed by layers embedded in the substrate.

13. The microphone of claim 1 further comprising an encapsulating material at least partially covering the IC.

14. The microphone of claim 13 further comprising an encapsulating material confinement structure disposed between the MEMS transducer and the IC, wherein the encapsulating material confinement structure at least partially confines the encapsulating material around the IC.

15. The microphone of claim 14, the substrate defining a cavity including an IC mounting surface on which the IC is mounted, a wall portion of the cavity forming the encapsulating material confinement structure, the MEMS transducer mounted on a MEMS mounting surface of the substrate, the MEMS mounting surface elevated relative to the IC mounting surface.

16. The microphone of claim 15, wherein the cover is mounted on a cover mounting surface of the substrate, the MEMS mounting surface elevated relative to the cover mounting surface, and the cover mounting surface elevated relative to the IC mounting surface.

17. The microphone of claim 15, wherein the MEMS mounting surface is a platform that completely surrounds a periphery of the cavity.

18. The microphone of claim 14, the first surface of the substrate defining a second opening into the embedded cavity.

19. The microphone of claim 14 further comprising a resistor and a capacitor formed by layers embedded in the substrate.

20. The microphone of claim 13, the MEMS transducer and IC are mounted on coplanar surface portions of the substrate, the encapsulating material confinement structure is a wall portion protruding above the coplanar surface portions of the substrate, wherein the encapsulating material is at least partially confined by the wall portion.