Composite microphone boot to optimize sealing and mechanical properties

• US 8,515,113 B2
• Filed: 08/19/2010
• Issued: 08/20/2013
• Est. Priority Date: 08/19/2010
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Rothkopf, Fletcher R., Hobson, Phillip M., Mittleman, Adam, Shedletsky, Anna-Katrina
• Primary Examiner(s): Goins, Davetta W
• Assistant Examiner(s): ETESAM, AMIR HOSSEIN
• Application Number:
  US12/859,711
• Publication Number:
  US 20120046780A1
• Time in Patent Office: 1,097 Days
• Field of Search: 381/355, 381/369, 381/375
• US Class Current: 381/369
• CPC Class Codes: H04R 1/02 Casings; Cabinets ; Supports therefor; Mountings therein H04R1/28 takes precedence ; attachments for microphones H04R1/08; mounting of transducers in earpieces H04R1/1075
• CPC Class Codes: H04R 2499/11 Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
• CPC Class Codes: H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182
• CPC Class Codes: Y10T 29/49005 Acoustic transducer

Abstract

A microphone assembly for an electronic device is described. The microphone assembly can include a microphone, a microphone boot and a printed circuit board. The microphone boot can be a composite microphone boot that is formed from multiple materials. A hardness of the each of the materials used in the microphone boot can be selected to improve sealing integrity and reduce shock transmission. In one embodiment, the composite microphone boot can be formed using a double-shot injection molding process.

Claims

1. A composite microphone boot comprising:

a first end cap shaped to conform to a curved interior surface of a portable computing device;

a second end cap shaped to conform to an exterior surface of a microphone;

a center portion disposed between the first end cap and the second cap, the center portion, the first end cap and the second cap surrounding a hollow interior portion configured to direct sound entering via an aperture in a housing of a portable computing device to the microphone wherein the first end cap and the second end cap are formed from at least one first material, the center portion is formed from a second material that separates the first end cap and the second end cap such that the first end cap and the second end cap do not touch each other, and the second material is softer material than the at least one first material to act as a shock absorber during operation of the portable computing device.

2. The composite microphone boot of claim 1, wherein the at least one first material is at least one silicon based plastic.

3. The composite microphone boot of claim 1, wherein the composite microphone boot is formed during a double shot injection molding process.

4. The composite microphone boot of claim 1, wherein the first end cap, the second end cap and the center portion are separately formed.

5. The composite microphone boot of claim 4, wherein the first end cap, the second end cap and the center portion are installed and held in place within the portable computing device via a mechanical restraint without physically bonding the first end cap, the second end cap and the center portion to one another.

6. The composite microphone boot of claim 1, wherein the microphone boot is cylindrically shaped.

7. A microphone assembly comprising:

a circuit board;

a microphone coupled to the circuit board;

a composite microphone boot bonded to the microphone comprising a center portion disposed between a first end cap and a second end cap, the center portion, the first end cap and the second cap surrounding a hollow interior portion configured to direct sound entering via an aperture in a housing of a portable computing device to the microphone wherein the first end cap and the second end cap are formed from at least one first material of at least one first durometer, the center portion is formed from a second material of a second durometer and wherein the center potion separates the first end cap and the second end cap such that the first end cap and the second end cap do not touch each other and the second durometer is of a different hardness than the first durometer to configure the composite microphone boot to act as a shock absorber during operation of the portable computing device.

8. The microphone assembly of claim 7, wherein the second end cap is bonded to an exterior surface of the microphone via a pressure sensitive adhesive (PSA).

9. The microphone assembly of claim 7, wherein an upper surface of the end cap is curved to conform to an interior surface of the housing of the portable computing device.

10. The microphone assembly of claim 7, where the first end cap and the second cap are formed from softer materials than the center portion.

11. The microphone assembly of claim 7, wherein the first end cap and the second end cap are formed from harder materials than the center portion.

12. The microphone assembly of claim 7, wherein a thickness of the center portion surrounding the hollowing interior portion varies.

13. A portable electronic device comprising:

a housing;

a microphone disposed within an interior of the housing; and

a composite microphone boot configured to provide a sound conduit between an aperture in the housing and an exterior surface of the microphone, said composite microphone boot comprising;

     1) a first end cap bonded to the microphone,

     2) a second end cap bonded to an interior surface of the housing and

     3) a center portion disposed between the first end cap and the second end cap that separates the first end cap and the second end cap such that the first end cap and the second end cap do not touch each other;

wherein the first end cap and the second end cap are formed from a hard material and the center portion of the composite microphone boot is formed from a shock absorbing material that is softer than the hard material.

14. The portable electronic device of claim 13, wherein a sound isolation within the sound conduit is greater than 40 Decibels.

15. The portable electronic device of claim 13, wherein the first end cap and the second end cap are proximately identically shaped.

16. The portable electronic device of claim 13, wherein the first end cap and the second end cap are bonded to the microphone and the interior surface of the housing, respectively, via a pressure sensitive adhesive.

17. The portable electronic device of claim 13, wherein the interior surface of the housing is curved.

18. The portable electronic device of claim 13, wherein the composite microphone boot is secured within the housing such that it is under a compressive force to increase a seal integrity between the composite microphone boot and the interior surface of the housing and to increase a seal integrity between the composite microphone boot and the microphone.

19. The portable electronic device of claim 18, wherein a pre-secured thickness of the center portion of the composite microphone boot is greater than a secured thickness of the center portion.

20. A method of manufacturing a portable computing device comprising:

determining dimensions and materials to use for a composite microphone boot;

forming the composite microphone boot according to the determined dimensions and the determined materials wherein the composite microphone boot comprises a center portion formed from a first material that separates a first end cap and a second cap such that the first end cap and the second end cap do not touch each other, the first end cap and the second end cap each formed from a second material that is harder than the first material;

attaching the formed composite microphone boot to a microphone; and

attaching a microphone assembly including the composite microphone boot, the microphone and a circuit board to a housing of a portable computing device wherein the microphone assembly is attached such that the composite microphone boot is compressed to increase a sealing integrity of a first seal between the microphone boot and an interior surface of the housing and to increase a sealing integrity a second seal between the microphone boot and the microphone.

21. The method of claim 20, integrally forming the center portion, the first end cap and the second cap in a double shot molding process.

22. A non-transitory computer readable medium for storing computer code executed by a processor in a computer aided manufacturing process comprising:

computer code for forming a composite microphone boot wherein the composite microphone boot comprises a center portion formed from a first material that separates a first end cap and a second cap such that the first end cap and the second end cap do not touch each other, the first end cap and the second end cap each formed from a second material that is harder than the first material;

computer code for attaching the formed composite microphone boot to a microphone coupled to a printed circuit board; and

computer code for attaching a microphone assembly including the composite microphone boot, the microphone and the printed circuit board to a housing of a portable computing device wherein the microphone assembly is attached such that the composite microphone boot is compressed to increase a sealing integrity of a first seal between the microphone boot and an interior surface of the housing and to increase a sealing integrity a second seal between the microphone boot and the microphone.