PATENT DOCUMENT

Publication Number: US-10162390-B2
Application Number: US-201614997442-A
Country: US
Kind Code: B2

Title: Hybrid acoustic EMI foam for use in a personal computer

Abstract:
The described embodiments relate to an electronic assembly that includes multiple varied electrical components. In some embodiments, the electronic assembly can include electrical components susceptible to electromagnetic interference (EMI). In one particular embodiment, an antenna can be positioned along an exterior surface of an enclosure of the electronic assembly and another electrical component can be disposed within the enclosure. When the other electrical component is a speaker component, a port or opening for emitting audio output can be protected from EMI by surrounding the port with a conductive gasket that includes a closed cell foam substrate wrapped in an electrically conductive fabric. In some embodiments, the closed cell foam substrate defines a number of perforations that are plated with an electrically conductive material.

Claims:
What is claimed is: 
     
       1. An audio assembly, comprising:
 an assembly housing comprising walls that define a port, wherein at least one wall of the assembly housing has an opening defined by the port; 
 an audio speaker positioned in the port; and 
 a gasket comprising a foam ring and an electrically conductive fabric at least partially surrounding the foam ring, the gasket positioned on the assembly housing and surrounding the opening, 
 wherein the gasket shields the audio speaker from electromagnetic interference (EMI) generated externally to the assembly housing. 
 
     
     
       2. The audio assembly of  claim 1 , wherein the gasket comprises:
 a hole extending through the foam ring; and 
 a plated surface defining an inner surface of the hole, the plated surface formed from an electrically conductive material, the plated surface preventing the EMI from passing through the hole. 
 
     
     
       3. The audio assembly of  claim 2 , wherein a portion of the foam ring remains uncovered to define an uncovered portion of the foam ring, and wherein the hole and the plated surface are positioned in the uncovered portion. 
     
     
       4. The audio assembly of  claim 1 , further comprising an antenna positioned outside of the assembly housing on the walls, wherein the walls comprise:
 a first wall through which the opening is formed; and 
 a second wall different from the first wall, wherein the antenna is positioned on the second wall, and wherein the gasket shields the audio speaker at the opening from the EMI caused by EM energy from the antenna. 
 
     
     
       5. The audio assembly of  claim 4 , wherein the assembly housing is formed of non-conductive material and wherein portions of the assembly housing are covered with conductive material that shields portions of the assembly housing from the EMI emitted by the antenna. 
     
     
       6. The audio assembly of  claim 4 , wherein the audio speaker further comprises a magnet that emits a magnetic field, and wherein the gasket blocks the magnetic field emitted by the magnet from passing through the gasket and interfering with the antenna when the antenna is active. 
     
     
       7. The audio assembly of  claim 1 , wherein the audio speaker comprises an acoustic membrane covering the port, and wherein the acoustic membrane is non-electrically conductive. 
     
     
       8. A portable electronic device, comprising:
 an enclosure comprising a plurality of openings, the enclosure defining an internal volume; 
 an assembly housing disposed in the internal volume, the assembly housing comprising a first wall and a second wall, the assembly housing further defining an audio port that defines an opening that is aligned with the plurality of openings; 
 an audio transducer positioned in the audio port; 
 an antenna disposed on the first wall, the antenna external to the audio port; and 
 a gasket disposed on the second wall, the gasket comprising a foam ring and an electrically conductive fabric at least partially surrounding the foam ring and engaged with an interior surface of the enclosure, wherein the gasket surrounds the opening and engages the enclosure, wherein the gasket defines an acoustic pathway from the audio transducer to the plurality of openings, and wherein the gasket further defines a shield from electromagnetic interference (EMI) caused by EM energy emitted by the antenna. 
 
     
     
       9. The portable electronic device of  claim 8 , wherein the gasket further comprises:
 a hole extending through the foam ring; and 
 a plated surface defining an inner surface of the hole, the plated surface formed from an electrically conductive material, the plated surface preventing the EMI from passing through the hole. 
 
     
     
       10. The portable electronic device of  claim 8 , wherein:
 the enclosure comprises a top case and a bottom case, the top case and the bottom case formed from a metal, 
 the top case comprises the plurality of openings, and 
 the bottom case comprises internal walls that receive the assembly housing. 
 
     
     
       11. The portable electronic device of  claim 10 , further comprising a mask extending from the top case, wherein the top case and the bottom case define an opening that allows the antenna to communicate with a device external with respect to the enclosure, and wherein the mask at least partially hides the antenna. 
     
     
       12. The portable electronic device of  claim 8 , wherein the enclosure further comprises:
 a display housing that carries a display monitor; 
 a base portion rotatably coupled with the display housing, the base portion comprising a top case, wherein the plurality of openings are formed in the top case; and 
 a keyboard assembly and a touch pad, the keyboard assembly and the touch pad carried by the base portion. 
 
     
     
       13. A method for forming a portable electronic device having an enclosure and an antenna, the method comprising:
 providing a conductive gasket comprising:
 a substrate comprising a foam ring, and 
 an electrically conductive fabric at least partially surrounding the foam ring; 
 
 securing the conductive gasket to an assembly housing, the assembly housing comprising walls that define a port that receives an audio speaker, wherein at least one wall has an opening that is defined by the port; 
 securing the antenna with the walls, wherein the antenna is external with respect to the port; and 
 engaging the conductive gasket with the enclosure, wherein the conductive gasket surrounds the opening and shields the audio speaker from electromagnetic interference (EMI) caused by EM energy emitted by the antenna. 
 
     
     
       14. The method of  claim 13 , wherein the audio speaker comprises a magnet that emits a magnetic field, and wherein the conductive gasket blocks the magnetic field emitted by the magnet from passing through the conductive gasket and interfering with the antenna when the antenna is active. 
     
     
       15. The method of  claim 13 , wherein providing the conductive gasket comprises:
 covering only a portion of the substrate with the electrically conductive fabric to defined an exposed end of the substrate that is free of the electrically conductive fabric. 
 
     
     
       16. The method of  claim 15 , wherein the foam substrate comprises a hole, and wherein the hole comprises a plated surface formed from an electrically conductive material. 
     
     
       17. The method of  claim 16 , wherein the hole is positioned in the substrate proximate the exposed end of the substrate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims the benefit of priority under 35 U.S.C § 119(e) to i) U.S. Provisional Application No. 62/104,611, filed on Jan. 16, 2015, and titled “HYBRID ACOUSTIC EMI FOAM FOR USE IN A PERSONAL COMPUTER,” and ii) U.S. Provisional Application No. 62/106,667, filed on Jan. 22, 2015, and titled “HYBRID ACOUSTIC EMI FOAM FOR USE IN A PERSONAL COMPUTER,” the disclosure of each is incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The described embodiments relate generally to electromagnetic shielding. In particular, the present embodiments relate to methods and apparatuses for shielding an audio assembly having an antenna coupled to an exterior surface of a housing of the audio assembly. 
     BACKGROUND 
     As electronic devices are reduced in size while maintaining or increasing in complexity, various components that were conventionally designed with discrete packaging can be integrated into multi-component assemblies. One difficulty faced by designers desiring to group components together is electromagnetic interference (EMI). Because many components emit at least small amounts of EMI, placing components in direct contact can make it substantially more difficult to isolate the integrated components in a way that prevents the components from interfering with one another. Unfortunately, when an electrical component is exposed to EMI emitted by another one of the integrated electrical components, serious component degradation or in some cases even permanent damage to one or more of the integrated components can occur. Components that facilitate wireless transmissions, such as antennas, can be even more susceptible to interference and are oftentimes more likely to cause interference to other nearby electrical components. 
     SUMMARY 
     This paper describes various embodiments that relate to methods and apparatus for shielding a speaker assembly from ingress of electromagnetic interference (EMI) through a port opening of the speaker assembly. 
     In one aspect, an audio assembly is described. The audio assembly may include an assembly housing defining an interior volume and may include an audio port that opens to an audio transducer. The audio assembly may further include a gasket that includes an electrically conductive material, the gasket surrounding the audio port. The audio assembly may further include an antenna disposed along a wall of the assembly housing. In some embodiments, the gasket blocks electromagnetic interference (EMI) emitted by the antenna from passing through the gasket and entering the audio port. 
     In another aspect, a portable electronic device is described. The portable electronic device may include an enclosure formed from a metal and may include a plurality of openings. The portable electronic device may further include an assembly housing disposed in the enclosure and may include an audio transducer positioned to emit sound through the plurality of openings. The portable electronic device may further include an antenna disposed on the assembly housing. The portable electronic device a gasket disposed on the assembly housing and engaging the enclosure. The gasket may define an acoustic pathway from the audio transducer to the plurality of openings. In some embodiments, the gasket further defines a shield from electromagnetic interference (EMI) emitted by the antenna. 
     In another aspect, a method for forming a portable electronic device having an enclosure and an antenna is described. The method may include wrapping a foam substrate with an electrically conductive fabric to form a conductive gasket. The method may further include securing the conductive gasket to an audio assembly disposed in the portable electronic device. The audio assembly may include an assembly housing. The method may further include engaging the conductive gasket with the enclosure. In some embodiments, the conductive gasket blocks electromagnetic interference (EMI) emitted by the antenna from passing through the conductive gasket. 
     Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the embodiments, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG. 1  shows a perspective view of an embodiment of an electronic device, in accordance with the described embodiments; 
         FIG. 2  shows a perspective view of an audio assembly that includes an antenna; 
         FIG. 3  shows a perspective view of the audio assembly secured to a bottom case of an electronic device; 
         FIG. 4  shows an enlarged cross sectional view of the audio assembly and the bottom case shown in  FIG. 3 , taken along line A-A; 
         FIG. 5  shows a perspective view of an embodiment of a conductive gasket, in accordance with the described embodiments; 
         FIG. 6  illustrates a cross sectional views of the conductive gasket shown in  FIG. 5 , taken along lines B-B; 
         FIG. 7  illustrates a cross sectional views of the conductive gasket shown in  FIG. 5 , taken along lines C-C; 
         FIG. 8  shows a perspective view of a top case secured with a bottom case to enclose an audio assembly, in accordance with the described embodiments; 
         FIG. 9  shows an enlarged cross sectional view of audio assembly, the top case, and the bottom case shown in  FIG. 8 , taken along line D-D; 
         FIG. 10  shows a partial cross sectional view of an embodiment of an audio assembly having a first gasket surrounding a second gasket, in accordance with the described embodiments; 
         FIG. 11  shows a partial cross sectional view of an alternate embodiment of an audio assembly, in accordance with the described embodiments; 
         FIG. 12  shows a partial cross sectional view of an embodiment audio assembly having a first gasket positioned on an interior portion of a second gasket, in accordance with the described embodiments; 
         FIG. 13  shows a partial cross sectional view of an alternate embodiment of an audio assembly, in accordance with the described embodiments; and 
         FIG. 14  shows a flowchart representing a method for forming a portable electronic device having an enclosure and antenna, in accordance with the described embodiments. 
     
    
    
     Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings may be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     Combination of subassemblies within electrical devices can result in numerous efficiencies and space savings. In many cases, the combined electrical devices can share resources such as power and data inputs, shock protection, and attachment mechanisms. The following disclosure relates to combining an antenna component with another electrical component without degrading either the antenna component or the other electrical component. In the case of a communications antenna that periodically emits high-energy radio frequency (RF) signals, effective grounding and shielding of the components can be particularly important. In particular, when combining the communications antenna with a speaker assembly (or audio assembly), speaker ports (audio ports) of the speaker assembly can be particularly vulnerable to allowing electromagnetic interference (EMI) to enter into the speaker assembly. Unfortunately, materials well-suited for defining an audio pathway, or an acoustic pathway, out of the speaker assembly are often formed of non-electrically conductive materials, such as a closed cell foam or an open cell foam, that do not form an effective barrier against EMI. 
     One way to mitigate ingress of EMI into the speaker assembly is to utilize a hybrid gasket for protecting the speaker port of an assembly housing of the speaker assembly from the intrusion of EMI. The hybrid gasket may include conductive closed cell foam wrapped in an electrically conductive fabric. By securing the hybrid gasket to an exterior surface of the assembly housing along a perimeter of the opening defined by the speaker port and compressing the hybrid gasket between an interior surface of a device housing and the exterior surface of the assembly housing, the hybrid gasket effectively blocks any direct pathway to the opening defined by the speaker block. The electrical conductivity of the hybrid gasket allows electrically conductive material of the assembly housing to be grounded with the interior surface of the device housing by way of the hybrid gasket. In this way, a faraday cage is created that extends around the assembly housing and the hybrid gasket, effectively preventing EMI emitted by the communications antenna from reaching the speaker assembly and likewise preventing magnetic components associated with the speaker assembly from interfering with the communications antenna. 
     Use of a foam material, including closed or open cell foam, to form the hybrid gasket also beneficially affects acoustic characteristics of the speaker assembly as the foam material may attenuate audio signals passing through it, thereby effectively confining the audio signal to a desired cavity and/or exit. In this regard, closed or open cell foam formed from the foam material may be referred to as an acoustic sealing foam. One way to make closed cell foam conductive is to perforate a closed cell foam substrate and then plate the perforations with an electrically conductive material (or materials). In some embodiments, the perforations can be selectively arranged within the closed cell foam substrate so that the perforations are concentrated near portions of the closed cell foam substrate that are not covered by the electrically conductive fabric. The conductive perforations can reduce the ingress of EMI through all portions of the hybrid gasket, but are particularly helpful for protecting portions of the closed cell foam not otherwise covered by conductive fabric. 
     These and other embodiments are discussed below with reference to  FIGS. 1-14 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  shows a perspective view of an embodiment of an electronic device  100 , in accordance with the described embodiments. In some embodiments, the electronic device  100  is a mobile wireless communication device, such as a smartphone. In the embodiment shown in  FIG. 1 , the electronic device  100  is a portable electronic device, such as a laptop computer. As shown, the electronic device  100  may include an enclosure  102  designed to carry several internal components. As shown, the enclosure  102  is formed from a metal that may include aluminum or an aluminum alloy. However, in other embodiments, the enclosure  102  is formed form non-metals, such as plastic. 
     The enclosure  102  may include a display housing  104  coupled with a base portion  106 , with the display housing  104  attached with the base portion  106  in a rotatable manner. The display housing  104  may be designed to carry a display monitor  108  designed to present visual content. The base portion  106  may be designed to carry a keyboard assembly  110  and a touch pad  112 , along with several internal components, such as one or more audio speakers (not shown) that emit audible sound. As shown, the base portion  106  may include a top case  114  that includes openings  116 , or perforations, extending through the top case  114 . Some openings  116  may extend entirely through the top case  114  to allow, for example, audible sound from the audio speakers, or to allow wireless communication between an external device (not shown) and one or more antennae (not shown) disposed near the openings  116 . However, some of the openings  116  may extend only partially through the top case  114  to define several blind holes. Also, the openings  116  shown in  FIG. 1  may be exaggerated for purposes of illustrations, and the diameter of the openings  116 , and accordingly, the openings  116  themselves, may be smaller. 
       FIG. 2  shows a perspective view of an audio assembly  200  with an embedded antenna. The audio assembly  200  may include an assembly housing  202  to enclosure several components for the audio assembly  200 . In some embodiments, the assembly housing  202  is formed from one or more radio transparent materials, such as a polycarbonate (“PC”) material (or materials). A “radio transparent” material may be defined as a material (or materials, in some cases) that allows RF transmissions through the material. The RF transmission may include, for example, a frequency on the order of gigahertz (“GHz”), and accordingly, may include RF transmission in the form of Wi-Fi or Bluetooth transmission to and/or from the electronic device  100  (shown in  FIG. 1 ). Also, the assembly housing  202  may include at least one wall covered with a radio opaque conductive layer. A “radio opaque” layer may be defined as a layer that includes a material (or materials) that prevents or blocks RF transmission from passing through the material. The assembly housing  202  can be formed of multiple housing components that can be joined or snapped together to surround audio circuitry disposed within the assembly housing  202 . 
     The assembly housing  202  may include a housing wall  204  provides a surface upon which an antenna  206  can be affixed. The antenna  206  may be suitable for RF transmission for Wi-Fi communication, which may include a wireless communication channel between, for example, the electronic device  100  (shown in  FIG. 1 ) and a router electrically coupled with a modem. Further, the antenna  206  may be suitable for RF transmission for Bluetooth communication, which may include a wireless communication channel between, for example, the electronic device  100  (shown in  FIG. 1 ) and a mouse and/or a keyboard used with the electronic device  100 . Accordingly, the antenna  206  may be tuned to receive RF transmission having a frequency of 2.4 GHz or greater in order to communicate wireless with a device external with respect to an electronic device. In some embodiments, the antenna  206  can be formed by selectively depositing electrically conductive material on the housing wall  204  in a geometry suitable for use as an antenna. For example, because a bottom surface of the assembly housing  202  is generally positioned upon an electrically conductive surface (such as a surface associated with a base portion  106  shown in  FIG. 1 ) that shields the bottom surface, the bottom surface of assembly housing  202  can have little or no electrically conductive material deposited thereon. Also, in some embodiments, the housing wall  204  can include no electrically conductive material at all but for the conductive material utilized to form the antenna  206 . Further, other walls that form the assembly housing  202  can be fully coated with an electrically conductive material to prevent intrusion of electromagnetic interference (EMI) through the assembly housing  202 . In some embodiments, shielding can be placed directly behind the antenna  206  within an interior volume defined by the assembly housing  202  to prevent radiation emitted by the antenna  206  from entering and interfering with circuitry disposed within the assembly housing  202 . 
     The antenna  206  can receive operating power from an internal connector  208  by way of a power conduit  210 . In some embodiments, the internal connector  208  can be a dedicated connector serving only to provide power and/or data to and from the antenna  206 . Circuitry and other components disposed within the assembly housing  202  can also receive power and data through electrically conductive pathways passing through the assembly housing  202 . For example, in some embodiments, the electrically conductive pathways can be embodied by a speaker connector  212 , which passes through a slot or opening in the assembly housing  202  so that power and/or data can be transferred to and from electrical components disposed within the assembly housing  202 . The audio assembly  200  may also include electrically conductive gaskets that are also configured to provide a well-defined pathway for audio generated by vibration of acoustic membranes (that form audio speakers), causing audible sound from the acoustic membranes to pass out of an electronic device housing (such as the enclosure  102  shown in  FIG. 1 ) within which the audio assembly  200  is disposed. For example, as shown in  FIG. 2 , the audio assembly  200  may include a first conductive gasket  214  and a second conductive gasket  216  that provide an acoustic pathway for audio generated by vibration of acoustic membranes from a first acoustic membrane  218  and a second acoustic membrane  220 , respectively. The first acoustic membrane  218  may be part of a first audio transducer (not shown) disposed in the assembly housing  202 , and the second acoustic membrane  220  may be part of a second audio transducer (not shown) and a second audio transducer (not shown) disposed in the assembly housing  202 . Also, both the first acoustic membrane  218  and the second acoustic membrane  220  may be formed from a non-electrically conductive material. 
     In some embodiments, the first conductive gasket  214  and the second conductive gasket  216  are formed primarily of closed cell foam. The assembly housing  202  may include a first port (or opening) and a second port that open to receive the first acoustic membrane  218  and the second acoustic membrane  220 , respectively. Accordingly, the first port and the second port may be referred to as a first audio port and a second audio port, respectively. Also, the assembly housing  202  may include a fastening feature  222  formed at one end of the assembly housing  202  and configured to receive a fastener for securing the audio assembly  200  to an electronic device housing. Further, in some embodiments, the antenna  206  is replaced by an operational component that emits EMI. However, the conductive gaskets may nonetheless prevent or mitigate EMI from interfering with the audio transducers. 
       FIG. 3  shows a perspective view of the audio assembly  200  secured to a bottom case  302  of an electronic device. The bottom case  302  may be designed to mate and couple with the top case  114  of the electronic device  100  (shown in  FIG. 1 ) to enclose components such as the audio assembly  200 . In this regard, the audio assembly  200  may be positioned in an electronic device such that the audio assembly  200  may generate audio transmission that leaves the openings  116  (shown in  FIG. 1 ) that extend entirely through the top case  114 . Further, the electronic device  100  (shown in  FIG. 1 ) may include two or more audio assemblies, each of which is substantially similar to that of the audio assembly  200 . Also, the bottom case  302  can be formed of a radio opaque material that may include aluminum or an aluminum alloy, similar to that of the enclosure  102  (shown in  FIG. 1 ). 
     The bottom case  302  includes a number of internal walls  304  that subdivide internal components supporting an electronic device associated with the audio assembly  200 . For example, the internal walls  304  may define a slot or partial opening to receive an audio assembly  200 . The bottom case  302  may also receive an internal connector  306  designed to engage and electrically couple with the internal connector  208  to provide battery power or externally supplied power to drive speakers and antennas of audio assembly  200 . In some embodiments, the internal connector  208  and the internal connector  306  can transfer both power and data between circuitry installed within the bottom case  302  and/or the audio assembly  200 . Also, in some embodiments, the internal connector  306  electrically couples and/or syncs the antenna  206  to a second antenna (not shown) disposed within or in communication with circuitry associated with the bottom case  302 . In some embodiments, the second antenna can be part of a second audio assembly (not shown) having an antenna similar to that of the antenna  206  that cooperates with the antenna  206  to receive and transmit wireless communications for an associated electronic device. 
       FIG. 4  shows an enlarged cross sectional view of the audio assembly  200  and the bottom case  302  shown in  FIG. 3 , taken along line A-A. Primarily, a partial cross sectional view of configuration of the first conductive gasket  214  is depicted. However, the configuration of the second conductive gasket  216  (shown in  FIG. 2 ) may be substantially similar to that of the first conductive gasket  214 . As shown, the first conductive gasket  214  is formed from a substrate  232  substantially surrounded by an electrically conductive fabric  234  in the form of a “U” shape. The substrate  232  may include a closed cell foam substrate. The electrically conductive fabric  234  may prevent or reduce an amount of electromagnetic interference (EMI) passing through the substrate  232  and into the assembly housing  202  through the first acoustic membrane  218 . A top wall of the assembly housing  202  can be covered by an electrically conductive layer  236 , thereby preventing EMI from passing through the top wall of the assembly housing  202 . In some embodiments, a thickness and positioning of the electrically conductive layer  236  can be selectively placed upon the assembly housing  202  to align with a pattern of RF energy emitted by the antenna  206 . 
     Also, the first acoustic membrane  218  may include an audio transducer configured to vibrate the first acoustic membrane  218  for generation of audible signals. The audio transducer may include a permanent magnet  242  and electromagnet  244 . The audio transducer can also include circuitry configured to convert audio signals received into audible sound by modulating an amount of current supplied to the electromagnet  244 . The permanent magnet  242  and/or electromagnet  244  may, at least periodically, generate magnetic fields that, without proper shielding, could cause electromagnetic interference that adversely affects operation of the antenna  206 . In this regard, the audio transducer can also include a metallic shunt  246  designed to concentrate magnetic field emitted by permanent magnet  242  in a direction toward the electromagnet  244 . Further, in some embodiments, the permanent magnet  242  and/or the electromagnet  244  may emit a magnetic field (not shown) that may extend beyond the first acoustic membrane  218 . However, in addition to the first conductive gasket  214  not only preventing EMI from reaching the audio assembly  200 , but the first conductive gasket  214  may also prevent the magnetic field from extending to, and interfering with, the antenna  206 . 
       FIG. 5  shows a perspective view of an embodiment of a conductive gasket  414 , in accordance with the described embodiments. The conductive gasket  414  shown in  FIG. 5  may be used with an audio assembly  200  in place of the first conductive gasket  214  (shown in  FIG. 2 ). An additional conductive gasket similar to the conductive gasket  414  may also replace the second conductive gasket  216  (shown in  FIG. 2 ). As depicted, the conductive gasket  414  may include a fabric-over-foam configuration. For example, an electrically conductive fabric  434  may wrap at least partially around a substrate  432 , which may include a closed cell foam substrate. However, opposing ends of the substrate  432  may remain partially uncovered by the electrically conductive fabric  434 . For example, the substrate  432  may include a first end  436  defining a first exposed end and a second end (not shown) opposite the first end  436  to define a second exposed end, with the exposed ends uncovered by the electrically conductive fabric  434 . In some cases, a conventional closed cell foam substrate would allow EMI to pass through the conductive gasket  414  due in part to the substrate  432  being at least partially uncovered by the electrically conductive fabric  434  at the exposed ends of the substrate  432 . However, the electrically conductive fabric  434  may be modified to overcome issues related to EMI transmission. 
     For example,  FIG. 6  illustrates a cross sectional view of the conductive gasket  414  shown in  FIG. 5 , taken along line B-B, showing how the substrate  432  can be perforated and plated to prevent or at least reduce an amount of EMI that passes through the exposed ends of the substrate  432 . The substrate  432  may include several through holes. A “through hole” may be defined as an opening that extends completely through a structure. For example, as shown in  FIG. 6 , the substrate  432  may include a first through hole  442  that passes entirely through the substrate  432 . The first through hole  442  may include an inner surface defining a generally cylindrical shape. However, the inner surface of the through holes may vary to include three or more discrete sides. Further, the first through hole  442  may include a plated surface  444  formed from an electrically conductive material, such as metal. Accordingly, the first through hole  442  may be electrically conductive. 
       FIG. 7  illustrates a cross sectional view of the conductive gasket  414  shown in  FIG. 5 , taken along line C-C, showing the substrate  432  having several through holes. Each through hole shown in  FIG. 7  may be similar to that of the first through hole  442  (shown in  FIG. 6 ). Accordingly, each of the through holes shown in  FIG. 7  may include a plated surface similar to that of the plated surface  444  (shown in  FIG. 6 ). For example, as shown in  FIG. 7 , the substrate  432  may include a second through hole  452  that includes a plated surface  454  formed from an electrically conductive material. The second through hole  452  and the plated surface  454  may be representative the remaining through holes and plated surfaces, respectively. Also, the through holes may be aligned in the z-axis at an interval that prevents EMI emitted by an antenna (such as the antenna  206 , shown in  FIG. 2 ) from passing through the exposed ends of the substrate  432  the remain uncovered by the electrically conductive fabric  434 , while the portions of the substrate  432  covered by the electrically conductive fabric  434  are shielded from EMI by both the electrically conductive fabric  434  and plated through holes. In some embodiments, the through holes can be offset from one another to increase a flexibility or elasticity of the substrate  432 . 
       FIG. 8  shows a perspective view of a top case  114  secured with a bottom case  302  to enclose an audio assembly  200  (shown in  FIG. 2 ). The top case  114  may define a number of key openings through which pressable keys of the keyboard assembly  110  can pass. The top case  114  may also define the openings  116 , with the openings  116  including least two sets of speaker openings extending through the top case  114  in order to provide outlets for audio generated by a pair of audio assemblies similar to that of the audio assembly  200  (shown in  FIG. 2 ). 
       FIG. 9  shows an enlarged cross sectional view of the audio assembly  200 , the top case  114 , and the bottom case  302  shown in  FIG. 8 , taken along line D-D. The cross sectional view in  FIG. 9  further shows the audio assembly  200  and various components of the audio assembly  200  positioned within the top case  114  and the bottom case  302 . The top case  114  may include a mask  462  at least partially masking an opening  464  proximate to the audio assembly  200 . The opening  464  may provide an RF pathway through which signals can leave and arrive at the antenna  206 . In some embodiments, the mask  462  is formed of a radio transparent material so that RF energy can pass unobstructed through the opening  464  defined by bottom case  302  and the top case  114 . 
       FIG. 9  further shows how the first conductive gasket  214  engages a channel defined by the top case  114 . The first conductive gasket  214  and the top case  114  can cooperate to prevent EMI from entering the audio assembly  200  through the first acoustic membrane  218  by sealing an audio pathway between the audio assembly  200  and openings  116  of the top case  114 . Also, the first conductive gasket  214  may compress based on opposing force received by the top case  114  and the bottom case  302 . Also, the internal walls  304  of the bottom case  302  can cooperate with a protrusion  118  of the top case  114  to shield most portions of an interior volume defined by the top case  114  and bottom case  302  from EMI emitted by the antenna  206 . Because the substrate  232 , which may be formed from closed cell foam, does not tend to absorb audio signals emitted by the first acoustic membrane  218 , the substrate  232  also efficiently conducts audio waves from the first acoustic membrane  218  out through the openings  116  that fully extend through the top case  114 . 
       FIGS. 10-13  illustrate alternate embodiments audio assemblies used with the electronic device  100  (shown in  FIG. 1 ). The gaskets shown and described in  FIGS. 10-13  may vary with respect to the conductive gasket. Also, for purposes of simplicity, some features of the audio assemblies may be removed. 
       FIG. 10  shows a partial cross sectional view of an embodiment of an audio assembly  500  having a first gasket  502  surrounding a second gasket  504 , in accordance with the described embodiments. In some embodiments, the first gasket  502  includes a flexible silicone. As depicted, the first gasket  502  can be curved to both accommodate compression of the audio assembly  500  against an internal surface of an electronic device housing (previously shown) and to position a broad flat surface of first gasket  502  against the internal surface for a robust seal. Also, in some embodiments, the second gasket  504  includes electrically conductive foam. Also, for purposes of acoustic performance, the second gasket  504  is generally formed from a closed cell foam substrate to reduce an amount of sound that escapes into other portions of the electronic device housing. Also, the audio assembly  500  shown in  FIG. 10  allows the first gasket  502  to create an air seal between the audio assembly  500  and an internal surface of a device housing. Also, in some embodiments, the second gasket  504  includes several through holes (not shown), with each through hole having a plated surface formed from an electrically conductive material. In other words, the second gasket  504  may be modified to include plated perforations previously described (see, for example,  FIGS. 5-7 ), which may form a faraday cage surrounding the audio assembly  500  to continue entirely around the second gasket  504 . This may prevent EMI penetration through a housing of the audio assembly  500 . 
       FIG. 11  shows a partial cross sectional view of an alternate embodiment of an audio assembly  600 , in accordance with the described embodiments. The first gasket  602  and the second gasket  604  may include any material (or materials) previously described for a first and second gasket (for example, as shown and described in  FIG. 10 ). As shown in  FIG. 11 , a first gasket  602  may surround a second gasket  604 . Also, the first gasket  602  may define an “L-shaped” configuration in one portion, and may also define a flat configuration in another portion. This configuration may be preferable in order to provide an enhanced acoustic seal for the audio assembly  600  in response to vibration of an acoustic membrane  618 . The configuration depicted in  FIG. 11  may be preferable when the first gasket  602  is formed from particularly flexible material and when the second gasket  504  (in  FIG. 10 ) and the second gasket  604  (in  FIG. 11 ) substantially seals to the interior surface of the housing. It should be noted that while the gaskets are not surrounded by a conductive fabric (such as the electrically conductive fabric  234 , shown in  FIGS. 5-7 ), in some embodiments, a conductive fabric wraps around one or more of the gaskets shown in  FIGS. 10 and 11 . 
       FIG. 12  shows a partial cross sectional view of an embodiment audio assembly  700  having a first gasket  702  positioned on an interior portion of a second gasket  704 , in accordance with the described embodiments. In other words, the second gasket  704  may surround the first gasket  702 . The first gasket  702  and the second gasket  704  may include any material (or materials) previously described for a first and second gasket (for example, as shown and described in  FIG. 10 ). In the configuration shown in  FIG. 12 , the first gasket  702  can have a greater effect on audio attenuation than the second gasket  704 , as the first gasket  702  defines the pathway through which audio signals pass during operation of the audio assembly  700 . Additionally, the first gasket  702  can be a conductive gasket so that the first gasket  702  passes electrical current between an exterior surface of an electrically device housing of the audio assembly  700  to an interior surface of the electrical device housing. In such a configuration, the second gasket  704  can be embodied as a closed cell or open cell foam as the second gasket  704  is not directly exposed to the audio signals exiting the audio assembly and would not tend to attenuate the audio signal. 
       FIG. 13  shows a partial cross sectional view of an alternate embodiment of an audio assembly  800 , in accordance with the described embodiments. As shown, the audio assembly  800  may include a first gasket  802  surrounded by a second gasket  804 , each of which may include any material (or materials) previously described for a first and second gasket (for example, as shown and described in  FIG. 10 ). Also, the first gasket  802  may include a flexible lip  806  extending from an interior portion of the first gasket  802 . In some embodiments, the flexible lip  806  can help to direct audio signals towards a central portion of a central opening defined by the first gasket  802 . By moving the audio signal towards the central portion of the central opening some reduction in audio signal attenuation can be achieved by a reducing an amount of interaction between surfaces of the first gasket  802  that define the central opening. It should be noted that the flexible lip  806  could be included in any of the previously described embodiments. 
       FIG. 14  shows a flowchart  900  representing a method for forming a portable electronic device having an enclosure and antenna, in accordance with the described embodiments. In step  902 , a foam substrate with an electrically conductive fabric to form a conductive gasket. The foam substrate may be a closed cell foam substrate. Also, the foam substrate may include one or more through holes extending through the foam substrate, with each through hole receiving a plated surface formed from an electrically conductive material. Also, the electrically conductive fabric may extend partially around the foam substrate to define a “U” shape configuration. Further, the electrically conductive fabric may extend partially around the foam substrate such that the ends of the foam substrate are not exposed to the electrically conductive fabric. 
     In step  904 , the conductive gasket is secured to an audio assembly disposed in the portable electronic device. The audio assembly may include several features, such as comprising assembly housing and at least one audio transducer designed to emit audio sound. The audio transducer may emit the audible sound from the assembly housing via an audio port in the assembly housing. Also, the conductive gasket may surround the audio port and define an audio pathway for the audio transducer. 
     In step  906 , the conductive gasket engages the enclosure. The enclosure may be formed from a metal, such as aluminum or an aluminum alloy. Also, in some embodiments, the enclosure includes a top case and a bottom case, with the top case having several openings. Some of the several opening may be positioned in the top case such to further define the audio pathway in conjunction with the conductive gasket. Also, in some embodiments, the antenna is secured with the assembly housing. However, with the antenna disposed within the enclosure, and in particular, between the top case and the bottom case, the conductive gasket may block electromagnetic interference (EMI) emitted by the antenna from passing through the conductive gasket. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20160115
Publication Date: 20181225
Grant Date: 20181225
Priority Date: 20150116
Inventors: SWEET, EDWARD T.
GUTERMAN, Jerzy S.
FARAHANI, HOUTAN R.
Crosby, Justin D.
BOOTHE, DANIEL K.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/1688", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1688", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 56408904