PATENT DOCUMENT

Publication Number: US-9215833-B2
Application Number: US-201313839903-A
Country: US
Kind Code: B2

Title: Electronic device with heat dissipating electromagnetic interference shielding structures

Abstract:
An electronic device may have a metal electromagnetic interference shielding enclosure. The enclosure may have a bottom wall, vertical sidewalls that extend upwards from the bottom wall, and a lid that covers the enclosure to define an interior cavity. Power supply components and other electrical components may be mounted within the interior cavity. A printed circuit board on which integrated circuits and other components are mounted may have an upper surface that faces the bottom wall of the enclosure and an opposing lower surface that faces a metal plate. Fence structures may be used to help shield components mounted on the printed circuit. Heat may be dissipated from components on the printed circuit into the bottom wall and into the metal plate. A plastic housing may be used to house the shielding enclosure, printed circuit board, components mounted on the printed circuit board, and the metal plate.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a first printed circuit; 
 at least a first electrical component mounted on the first printed circuit; 
 a metal electromagnetic interference shielding enclosure having a bottom wall and vertical sidewalls that form an interior cavity in which the first electrical component and the first printed circuit are mounted; 
 a second printed circuit; and 
 at least a second electrical component mounted on the second printed circuit, wherein the second electrical component is adjacent to the bottom wall so that heat from the second electrical component dissipates through the metal electromagnetic shielding enclosure. 
 
     
     
       2. The apparatus defined in  claim 1  further comprising:
 at least a third electrical component mounted on the second printed circuit board, wherein the second and third electrical components are mounted on opposing sides of the second printed circuit board. 
 
     
     
       3. The apparatus defined in  claim 2  further comprising a metal plate, wherein the metal plate is configured to dissipate heat from the third electrical component. 
     
     
       4. The apparatus defined in  claim 3  further comprising:
 a first thermally conductive elastomeric pad between the second electrical component and the bottom wall; and 
 a second thermally conductive elastomeric pad between the third electrical component and the metal plate. 
 
     
     
       5. The apparatus defined in  claim 4  further comprising a plastic housing in which the metal electromagnetic interference shielding enclosure is mounted. 
     
     
       6. The apparatus defined in  claim 5  wherein the plastic housing has first and second structures that are attached using engagement features and wherein the vertical sidewalls have grooves that are configured to accommodate at least some of the engagement features during assembly. 
     
     
       7. The apparatus defined in  claim 1  further comprising a plastic insert in an opening in the bottom wall. 
     
     
       8. The apparatus defined in  claim 7  further comprising metal rods that pass through the plastic insert. 
     
     
       9. The apparatus defined in  claim 8  wherein the first printed circuit board has contacts coupled to the metal rods and wherein the second printed circuit board has contacts coupled to the metal rods. 
     
     
       10. The apparatus defined in  claim 9  wherein the first electrical component comprises a power supply component and wherein the metal rods convey power from the first printed circuit board to the second printed circuit board. 
     
     
       11. The apparatus defined in  claim 3  further comprising an antenna on a corner of the second printed circuit board. 
     
     
       12. The apparatus defined in  claim 11  further comprising a corner recess in the metal plate that overlaps the antenna. 
     
     
       13. The apparatus defined in  claim 3  further comprising a connector mounted to an edge of the second printed circuit board. 
     
     
       14. The apparatus defined in  claim 13  wherein the metal plate has protrusions that define a recess that receives the connector. 
     
     
       15. The apparatus defined in  claim 1  further comprising a conductive fence that is mounted to the second printed circuit board and that surrounds the second electrical component. 
     
     
       16. The apparatus defined in  claim 3  further comprising a thermally conductive elastomeric pad between the second printed circuit board and the metal plate that conveys heat from the second electrical component through the metal plate. 
     
     
       17. The apparatus defined in  claim 16  wherein the metal plate has a plurality of different thicknesses to accommodate electrical components of different sizes that are mounted on the second printed circuit board. 
     
     
       18. An electronic device, comprising:
 a plastic housing; 
 internal structures mounted in the plastic housing, wherein the internal structures include a power supply enclosed within a metal shielding enclosure having a bottom wall, vertical sidewalls, and a lid; 
 a printed circuit board on which an integrated circuit is mounted; and 
 thermally conductive structures between the integrated circuit and the bottom wall that convey heat from the integrated circuit to the metal shielding enclosure. 
 
     
     
       19. The electronic device defined in  claim 18  wherein the printed circuit board has an upper surface on which the integrated circuit is mounted and an opposing lower surface and wherein the internal structures comprise a metal plate adjacent to the lower surface. 
     
     
       20. The electronic device defined in  claim 19  further comprising a thermally conductive elastomeric structure between the printed circuit board and the metal plate through which heat from the integrated circuit is conveyed to the metal plate. 
     
     
       21. Apparatus, comprising:
 a metal electromagnetic signal shielding enclosure having a bottom wall, vertical sidewalls that extend upwards from the bottom wall, and a lid that encloses an interior cavity; 
 power supply circuitry in the interior cavity; 
 an integrated circuit; 
 a metal plate that dissipates heat from the integrated circuit; and 
 a printed circuit board on which the integrated circuit is mounted, wherein the printed circuit board has an upper surface that faces the bottom wall and has an opposing lower surface that faces the metal plate. 
 
     
     
       22. The apparatus defined in  claim 21  wherein the integrated circuit is mounted on the upper surface and wherein the bottom wall dissipates heat from the integrated circuit. 
     
     
       23. The apparatus defined in  claim 21  wherein the integrated circuit is mounted on the lower surface and wherein the apparatus further comprises a thermally conductive elastomeric structure that conveys heat from the integrated circuit to the metal plate.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to radio-frequency shielding and thermal management structures for components in electronic devices. 
     Electronic devices often contain components such as radio-frequency transmitters and other circuits that use electromagnetic interference (EMI) shielding structures. Electromagnetic interference shielding structures may help prevent radio-frequency signals that are generated by one component from disrupting the operation of another component that is sensitive to radio-frequency interference. Electromagnetic shielding structures may be formed from metal shielding cans soldered to printed circuit boards. A typical shielding has an inner metal fence and an outer metal lid structure. 
     The operation of integrated circuits such as radio-frequency transmitters and other circuitry tends to generate heat. To properly dissipate heat that is generated during operation, heat sink structures may be thermally coupled to the exterior of an electromagnetic shielding can. To ensure satisfactory heat transfer from a shielded integrated circuit to a heat sink, a thermally conductive elastomeric pad may be interposed between the integrated circuit and the shielding can to fill air gaps between the integrated circuit and the shielding can and another thermally conductive elastomeric pad may be interposed between the shielding can and the heat sink. The use of multiple thermally conductive paths and separate heat sink and electromagnetic interference shielding structures tends to make designs of this type complex and costly and may reduce the efficacy of the overall structure in removing heat from a component during operation. 
     It would therefore be desirable to be able to provide improved ways in which to provide components in electronic devices with heat sinking and electromagnetic interference shielding structures. 
     SUMMARY 
     An electronic device may have a metal electromagnetic interference shielding enclosure. The enclosure may have a bottom wall, vertical sidewalls that extend upwards from the bottom wall, and a lid that covers the enclosure to define an interior cavity. Power supply components and other electrical components may be mounted within the interior cavity. For example, electrical components may be mounted to a dielectric substrate and installed within the interior cavity. The electromagnetic interference shielding enclosure may help prevent interference that is generated by the electrical components from interfering with the operation of external circuitry and may help prevent interference from external circuitry from reaching the internal electrical components. 
     A printed circuit board on which integrated circuits and other components are mounted may have an upper surface that faces the bottom wall of the enclosure and an opposing lower surface that faces a metal plate. Fence structures may be used to shield components mounted on the printed circuit. The fence structures may provide lateral shielding. Shielding below the components on the upper surface of the printed circuit may be provided using metal traces in the printed circuit. Shielding above the components on the upper surface of the printed circuit may be provided using the bottom wall of the shielding enclosure. 
     Heat may be dissipated from components on the printed circuit into the bottom wall of the enclosure and into the metal plate. The metal plate may have protrusions that form a recess into which connectors on the edge of the printed circuit are received. The metal plate may have different areas with different thicknesses to accommodate components on lower surface of the printed circuit board of different heights. 
     A plastic housing may be used to house the shielding enclosure, printed circuit board, components mounted on the printed circuit board, and the metal plate. 
     Further features, their nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device of the type that may be provided with electromagnetic interference shielding and thermal management structures in accordance with an embodiment. 
         FIG. 2  is a cross-sectional side view of an illustrative electronic device with electromagnetic interference shielding and thermal management structures in accordance with an embodiment. 
         FIG. 3  is an exploded perspective view of an illustrative electronic device with electromagnetic interference shielding and thermal management structures in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of a portion of an electronic device having electromagnetic interference shielding and thermal management structures in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative electronic device having a hollow metal enclosure that serves as an electromagnetic interference shielding and thermal management structure in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of a portion of an electronic device showing electromagnetic interference shielding and thermal management structures that include a shielding enclosure and a metal plate in accordance with an embodiment. 
         FIG. 7  is a cross-sectional side view of a portion of an electronic device in which connector mounting structures in a metal plate structure have been used to prevent undesired rotation of a connector on a printed circuit relative to the device in accordance with an embodiment. 
         FIG. 8  is a bottom view of an interior portion of an electronic device showing where screw holes may be located relative to components mounted in the device in accordance with an embodiment. 
         FIG. 9  is a perspective view of an interior portion of an electronic device having a electromagnetic interference shielding and thermal management structure without a lid in accordance with an embodiment. 
         FIG. 10  is a perspective view of the electromagnetic interference shielding and thermal management structure of  FIG. 9  with a shielding enclosure lid in accordance with an embodiment. 
         FIG. 11  is a flow chart of illustrative steps involved in assembling an electronic device that contains electromagnetic interference shielding and thermal management structures in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An electronic device may be provided with electronic components such as integrated circuits. These components may be provided with electromagnetic interference shielding and heat sinking structures. Electromagnetic interference shielding functions may be provided by mounting electrical components within the interior of a metal enclosure that serves to reduce electromagnetic signal interference while dissipating heat generated by components. Electromagnetic interference shielding structures with integrated thermal management features may therefore sometimes be referred to as electromagnetic interference shielding enclosures or structures or may sometimes be referred to as heat-sinking electromagnetic interference shielding enclosures. Additional heat sinking and shielding may be provided using additional metal structures such as a metal plate that is mounted beneath a metal enclosure. 
     An illustrative electronic device of the type that may be provided with an electromagnetic interference shielding enclosure that serves as a heat sink for electrical components is shown in  FIG. 1 . Electronic device  10  of  FIG. 1  has openings  14  in housing  12 . Openings  14  form connector ports for connectors such as Ethernet plugs, Universal Serial Bus connectors, power connectors, audio jacks, connectors for coaxial cables for television signals and other signals, and other connectors. Housing  12 , which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing  12  may be formed using a unibody configuration in which some or all of housing  12  is machined or molded as a single structure or can be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). 
     Electronic device  10  of  FIG. 1  may be a set-top box, a wireless access point, a router, a storage device, a device for providing still and moving images to an attached display such as a television or computer monitor, a cellular telephone, a handheld portable device such as a media player, a somewhat smaller portable device such as a wrist-watch device, a pendant device, other wearable or miniature device, gaming equipment, tablet computer, notebook computer, desktop computers, television, computer monitor, a computer integrated into a computer display, a hybrid device that includes the functionality of two or more devices such as these, or other electronic equipment. The use of a set-top box form factor in implementing device  10  is merely illustrative. 
     Device  10  may include internal structures such as printed circuits. Electrical components may be mounted on the printed circuits and may be electrically connected through conductive paths in the printed circuits and in external cables. Printed circuits in device  10  may include rigid printed circuit boards (e.g., printed circuits formed from fiberglass-filled epoxy or other rigid substrate material) and/or flexible printed circuits (e.g., printed circuit substrates formed from flexible polymer layers such as sheets of polyimide). Components that may be mounted on the printed circuits include power supply components, inductors, capacitors, resistors, integrated circuits, switches, connectors, sensors, wireless circuits, and other components. Some of these components and the printed circuits on which the components are mounted may be mounted within the interior of a shielding enclosure. For example, power supply components may be mounted within an interior cavity of a main shielding structure that has the shape of a hollow metal box. Other components may be mounted to the exterior of the shielding enclosure. Additional shielding structures and heat sinking structures such as metal plate structures may be used in covering the components that are mounted to the exterior of the shielding structure. 
     When mounted using arrangements such as these, the shielding enclosure structures may prevent signal interference from disrupting the operation of the shielded components and may prevent the interference signals from the shielded structures from escaping the shielding structures. Heat sinking may also be provided by the shielding structures to ensure that the components do not overheat. Shielding structures that are configured to perform heat sinking may be formed using electrically and thermally conductive materials such as aluminum, stainless steel, or other metals. If desired, other electrically and thermally conductive materials may be used such as plastics covered and/or filled with metal particles so that the plastics are thermally and electrically conductive, etc. 
     A cross-sectional side view of device  10  of  FIG. 1  taken along line  16  and viewed in direction  18  is shown in  FIG. 2 . As shown in  FIG. 2 , device  10  may include interior structures  24  (e.g., electrical components mounted in electromagnetic interference shielding and thermal management structures) and an exterior housing  12  that surrounds interior structures  24 . Exterior housing  12  may be formed from a cosmetically appealing material such as white or black plastic (as examples). Housing  12  may be formed from multiple housing structures such as base housing structure  12 B and top (upper) housing structure  12 A. Housing structure  12 B may have the shape of a planar rectangular rear housing member that lies in a horizontal plane (in the orientation of  FIG. 2 ). Housing structure  12 A may have the shape of an open box with a downwards facing opening. 
     Housing structure  12 B and housing structure  12 A may have interlocking structures such as engagement features  20  on housing structure  12 B and engagement features  22  on housing structure  12 A. To assemble device  10 , internal structures  24  may be mounted within housing structure  12 A. Screws  28  may be screwed into openings in housing bosses  26  on housing structure  12 A to secure internal structures  24  to housing structure  12 A. After internal structures  24  have been mounted in housing structure  12 A, rear housing structure  12 B may be pressed into place against the bottom of housing  12 , thereby causing engagement features  20  to engage with engagement features  22  and thereby couple rear housing member  12 B to housing member  12 A. 
     An exploded perspective view of interior structures  24  is shown in  FIG. 3 . As shown in  FIG. 3 , interior structures  24  may include open-topped box-shaped shielding enclosure  26 . Shielding enclosure  26  may have sidewalls such as four vertical sidewalls  28  that extend upwardly as integral portions of horizontal rectangular bottom wall  30 . Power supply components and other electrical components may be mounted within interior  32  of shielding enclosure  26 . A lid (cover) may be mounted on top of shielding enclosure  26  to enclose the components that have been mounted within shielding enclosure  26 . The lid and shielding enclosure  26  may be formed from an electrically and thermally conductive material such as metal. 
     Interior structures  24  (sometimes referred to as internal structures  24 ) may include one or more substrates such as one or more printed circuits  34 . Electrical components such as illustrative electrical component  40  may be mounted on one or both sides of each printed circuit  34 . Components such as component  40  may be integrated circuits, discrete components, or other electrical devices. In the  FIG. 3  example, there is a single component  40  mounted to the upper surface of printed circuit  34 . This is merely illustrative. In general, any suitable number of electrical components may be mounted on one or more printed circuit substrates such as substrate  34  if desired. 
     To provide electromagnetic signal interference shielding, component  40  may be surrounded by conductive shielding structures such as metal shielding structures  36 . Metal shielding structure  36 , which may sometimes be referred to as shielding fence structures or a shielding fence, may have the shape of a rectangular ring with a rectangular central opening such as opening  48  that receives one or more components such as component  40 . Conductive gasket  38  (e.g., a conductive rectangular ring formed from a material such as conductive elastomeric plastic, conductive fabric, conductive foam, conductive foam covered with conductive fabric, or other conductive gasket material) may be interposed between shielding fence  36  and the lower surface of rear wall  30  of enclosure  26 . Printed circuit  34  may include metal ground plane structures that run under structure  36  and components in opening  48  such as component  40 , thereby providing shielding below component  40 . Fence  36  may provide lateral shielding for component  40 . The lower surface of bottom wall  30  of enclosure  26  may provide shielding above component  40 . To ensure satisfactory electrical connect between gasket  38  and the lower surface of rear wall  30 , it may be desirable to remove insulating materials from the surface of conductive layer  30  (e.g., by etching away an oxide layer or removing an oxide layer by laser exposure, etc.). 
     Components such as component  40  may generate heat during operation. To help dissipate the heat that is generated, enclosure  26  may serve as a heat sink. Satisfactory thermal conduction between component  40  and the underside of wall  30  of enclosure  26  may be achieved by interposing a thermally conductive elastomeric material such as elastomeric gap filler pad  42  between the upper surface of component  40  and the corresponding lower surface of rear wall  30 . 
     With this type of arrangement, enclosure  26  may serve as a heat sink that helps to dissipate heat from component  40 . For example, heat from component  40  may travel up sides  28  to be dissipated by thermal conduction to the surrounding environment and through radiation. At the same time, enclosure  26 , in conjunction with peripheral shielding structures such as conductive fence  36 , lower shielding structures such as printed circuit  34 , and upper shielding structures such as bottom enclosure wall  30 , may be used to provide electromagnetic signal interference shielding for components on printed circuit board  34  such as component  40 . The enclosure formed by bottom wall  30 , sidewalls  28 , and a mating enclosure lid (not shown in  FIG. 3 ) may serve as shielding for components mounted within interior cavity  32  of enclosure  26 . Enclosure  26  may also help dissipate heat that is generated by the components mounted within interior  32  of enclosure  26 . 
       FIG. 4  is a cross-sectional side view of a portion of interior structures  24  of  FIG. 3  in an assembled state. As shown in  FIG. 4 , component  40  may be sandwiched between bottom wall  30  of enclosure  26  and printed circuit  34 . Heat may be dissipated from component  40  via thermally conductive elastomeric pad  42  (e.g., plastic filled with metal particles) and bottom wall  30  and other metal in enclosure  26 . Electromagnetic signal interference shielding may be provided by embedded ground plane traces such as metal traces  50  in printed circuit  34 , the sidewall shielding formed by fence structures  36  and gasket  38 , and the upper shielding formed by wall  30 . 
       FIG. 5  shows how an enclosure lid such as lid  52  may be used to seal the top opening of enclosure  26  and thereby form a completed shielding enclosure that surrounds components  56 . Components  56  in the interior cavity of enclosure  26  may be mounted on one or more substrates such as dielectric substrate  58  (e.g., a flexible printed circuit, a rigid printed circuit board, etc.). Components  58  may be power supply components for forming a power supply in device  10  such as transformer coils, capacitors, diodes, integrated circuits, inductors, and resistors or other electrical components. The shielding provided by enclosure  26  (including lid  52 ) may help prevent external interference signals from disrupting the operation of components  56  and may help prevent interference signals that are generated by components  56  from interfering with external components outside of enclosure cavity  32 . Connectors such as connector  54  may be mounted on printed circuit  34 . Connectors such as connector  54  may include digital data connectors such as Ethernet connectors, High-Definition Multimedia Interface (HDMI) connectors, and Universal Serial Bus connectors, power connectors, audio jacks, connectors for coaxial cables for video such as television signals and other signals, and other connectors. 
     Signals may be routed between components  56  and components on board  34  such as component  40  and connector  54  using wires, flexible printed circuit cables, other cables, conductive housing structures, or other conductive paths. As an example, metal rods (sometimes referred to as power studs) may be used to convey power between board  58  and board  34 , thereby allowing power supply circuitry formed from components  56  to be used in powering components on board  34  such as component  40 . 
     As cross-sectional side view of a configuration for device  10  in which interior structures  24  include metal rods is shown in  FIG. 6 . As shown in  FIG. 6 , components  56  may be mounted on printed circuit board  58 . Printed circuit board  58  may contain traces  60 . Traces  60  may be coupled to contact pads such as contact pads  64 . Metal rods  66  may respectively be used to form a positive power supply path and a ground power supply path through dielectric insert  88 . Screws  62  may be used to hold rods  66  against the lower surface of printed circuit  58 . Screws  70  may be used to hold rods  66  against the upper surface of printed circuit  34 . 
     Dielectric insert  88  may be a plastic member that is press fit into an opening in lower wall  30  of enclosure  26 . Dielectric insert  88  may insulate rods  66  from metal wall  30  and from each other. 
     Metal rods  66  may be coupled to contacts  68  on the surface of printed circuit  34 . Contacts  68  may be coupled to traces  50  in printed circuit  34 . Traces  50  may be used to distribute power from rods  66  to components such as component  40  on the upper surface of printed circuit  34  and, if desired, to components such as components  74  and  78  that are mounted on the opposing lower surface of printed circuit  34 . 
     The lower surface of printed circuit  34  may face metal plate  84 . Metal plate  84  may be used as a heat sink to help dissipate heat from electrical components mounted to board  34 . Metal plate  84  may, for example, dissipate heat from components that are mounted to the upper surface of printed circuit  34  such as component  40 . To help dissipate heat from component  40 , thermally conductive elastomeric pad  76  may be interposed between the lower surface of printed circuit  34  and upper surface  82  of metal plate  84 . Components such as components  74  and  78  that are mounted on the lower surface of printed circuit  34  can dissipate heat into metal plate  84  through respective thermally conductive elastomeric pads  72  and  80 . 
     The thickness of metal plate  84  can be different in different areas of metal plate  84 . For example, in region  86  in which plate  84  overlaps pad  76 , the thickness of plate  84  can be relatively large to minimize the thickness of elastomeric pad  76  and thereby enhance thermal conductivity for heat passing through pad  76  into plate  84 . In portions  90  of plate  84 , plate  84  may be thinner and may have different thicknesses to accommodate the different heights of components  74  and  80  on the lower surface of printed circuit  34 . If desired, fence structures and conductive gaskets such as fence  36  and gasket  38  may surround components such as components  74  and  78  on the underside of printed circuit  34  and may extend between printed circuit board  34  and plate  84  to provide shielding for components such as components  74  and  78  on the underside of printed circuit  34 . Components on the upper and lower surfaces of printed circuit  34  may also be shielded using shielding cans. 
       FIG. 7  is an end view of metal plate  84  showing how metal plate  84  may have vertically extending protrusions  84 P that form a recess that receives and supports connector  54 . As a user attaches a cable to connector  54  or detaches a cable from connector  54 , connector  54  may be twisted about rotational axis  92  in directions  94 . The support provided by protruding support structures such as integral protrusions  84 P on metal plate  84  may help connector  54  to resist twisting motion and thereby remain mounted satisfactorily to printed circuit  34 . 
     It may be desirable to attach metal plate  84  or other metal shielding and heat dissipating structures to internal structures  24  (e.g., bottom enclosure wall  30 ) using fasteners such as screws. To ensure that thermally conductive elastomeric pads in structures  24  are properly compressed against components mounted on the upper and lower surfaces of printed circuit  34 , screws or other fasteners for attaching plate  84  may be concentrated near to components on printed circuit  34  and the associated elastomeric pads on these components. As shown in the bottom view of internal structures  24  in  FIG. 8 , for example, screw holes and screws  96  may be concentrated around locations such as locations  98  that overlap electrical components on printed circuit  34  and associated elastomeric pads. 
     Plate  84  may, if desired, have corner recesses  100  (see, e.g., curved edges  104  in the corners of plate  84 , which form quarter-circle recesses  100  at the upper right and lower right corners of plate  84  in the orientation of  FIG. 8 ). Recesses  100  at the corners of plate  84  may be used to accommodate wireless communications structures such as antennas  102 . Antennas  102  may be inverted-F antennas or antennas of other types. Antennas  102  may include antenna resonating elements (e.g., inverted-F antenna resonating elements) formed from metal traces on the corners of printed circuit  34 . Metal plate  84  and other metal structures in internal structures  24  may be used in forming an antenna ground. Plate  84  and corner portions of enclosure  26  may be set back from the antenna resonating elements on printed circuit  34  to ensure that antennas  102  exhibit satisfactory bandwidth and antenna efficiency. The inverted-F antennas formed from the inverted-F antenna resonating elements and the antenna ground may be fed using coaxial cables, microstrip transmission lines, or other transmission line structures. 
       FIG. 9  is a perspective view of illustrative interior structures  24 . In the example of  FIG. 9 , enclosure  26  has a rectangular box shape with an upper rectangular opening that is configured to receive a lid. The lid has been removed in  FIG. 9 , exposing conductive gasket  106 , which runs around the periphery of the rectangular opening for enclosure  26 . Gasket  106  may be formed from conductive foam covered with conductive fabric or other conductive gasket material. Grooves  108  in walls  28  of enclosure  26  may accommodate engagement features on housing  12 A such as protrusions  22  ( FIG. 2 ) when interior structures  24  slide into the interior of member  12 A during assembly. Enclosure  26  may have corners recesses such as recesses  110  to accommodate antennas  102  on the corners of printed circuit  34 , as described in connection with  FIG. 8 . 
     In the illustrative configuration of  FIG. 10 , lid  52  has been mounted to the top of enclosure  26  so as to enclose components for a power supply or other components  56  ( FIG. 9 ) within the interior of enclosure  26 . 
     A flow chart of illustrative steps involved in assembling an electronic device that contains electromagnetic interference shielding and thermal management structures is shown in  FIG. 11 . 
     At step  200 , power supply components or other components  56  on a dielectric substrate such as printed circuit board  58  may be mounted in interior cavity  32  of shielding enclosure  26 . The components may form a power supply for device  56 . After mounting components  56  within cavity  32 , lid  52  may be used to cover the upper opening of shielding enclosure  26 . 
     At step  202 , shielding enclosure  26  may be installed within upper housing structure  12 A using screws  28 . An air gap may be formed between the exterior surfaces of shielding enclosure  26  and the opposing adjacent interior surfaces of housing structure  12 A to prevent hotspots from developing on housing  12 . 
     At step  204 , printed circuit board  34  and the components mounted on the upper and lower surfaces of printed circuit board  34  may be placed against bottom wall  30  of shielding enclosure  26 . 
     At step  206 , metal plate  84  may be mounted to printed circuit board  34  and other internal structures  24 . Screws  96  ( FIG. 8 ) may be distributed in a pattern that helps prevent board  34  from flexing as board  34  and the components on board  34  are compressed between metal plate  84  and lower wall  30  of enclosure  26 . 
     Assembly of electronic device  10  may be completed at step  208  by snapping housing structure  12 B to housing structure  12 A. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20130315
Publication Date: 20151215
Grant Date: 20151215
Priority Date: 20130315
Inventors: DOLCI DOMINIC E.
SATTERFIELD PHILLIP S.
SINHA VIKAS K.
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K7/20418", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0049", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K7/20854", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K9/0022", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K7/20436", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K7/205", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/20409", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/20436", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K7/20409", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/021", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0022", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K7/205", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K9/0022", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K7/20854", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/20418", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/20436", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0049", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 50071777