PATENT DOCUMENT

Publication Number: US-10219057-B2
Application Number: US-201715699064-A
Country: US
Kind Code: B2

Title: Audio module for an electronic device

Abstract:
An electronic device is disclosed that includes one or more sealed audio modules that are unaffected by changes in the internal pressure within the electronic device. The audio modules can also include one or more features that increase the audible bandwidth of the electronic device.

Claims:
What is claimed is: 
     
       1. An audio module for an electronic device, the audio module comprising:
 a driver assembly comprising:
 a diaphragm defining a speaker plane; and 
 a voice coil attached to the diaphragm and positioned adjacent one or more magnets; and 
 
 an enclosure surrounding the driver assembly and defining:
 a front volume positioned on a first side of the speaker plane and coupled to a sound port; 
 a back volume positioned on the first side of the speaker plane and on a second side of the speaker plane; and 
 a resonant cavity coupled to the front volume via a resonant cavity port and separated from the back volume by a resonant cavity cover. 
 
 
     
     
       2. The audio module of  claim 1  wherein a first portion of the resonant cavity is positioned on the first side of the speaker plane and a second portion of the resonant cavity is positioned on the second side of the speaker plane. 
     
     
       3. The audio module of  claim 1  wherein the back volume is further defined by a frame, the diaphragm and a rear cover attached to the frame. 
     
     
       4. The audio module of  claim 3  wherein the driver assembly includes a bottom flux plate that forms a portion of the rear cover. 
     
     
       5. The audio module of  claim 1  wherein a substantially U-shaped channel couples the front volume to the sound port. 
     
     
       6. The audio module of  claim 5  further comprising a panel of acoustic mesh positioned within the substantially U-shaped channel and partially embedded within one or more walls that define the substantially U-shaped channel. 
     
     
       7. The audio module of  claim 6  wherein the panel of acoustic mesh is oriented at an angle with respect to the speaker plane. 
     
     
       8. The audio module of  claim 1  wherein the resonant cavity is sized to resonate at a frequency that extends a bandwidth of the audio module. 
     
     
       9. The audio module of  claim 1  further comprising a barometric vent coupling the front volume to the back volume. 
     
     
       10. An audio module for an electronic device, the audio module comprising:
 a frame; 
 a driver assembly disposed within the audio module and including a diaphragm that defines a speaker plane; 
 a front cover attached to the frame and positioned parallel to and spaced apart from the diaphragm in a first direction, wherein the front cover, the diaphragm and the frame define a front volume; 
 a back volume positioned at least partially on a first side of the speaker plane and at least partially on a second side of the speaker plane; 
 a front volume aperture coupled to the front volume; 
 a rear cover attached to the frame and positioned parallel to and spaced apart from the diaphragm in a second direction that is opposite the first direction; and 
 a substantially U-shaped channel that couples acoustic energy from the front volume aperture to a sound port defined by the frame. 
 
     
     
       11. The audio module of  claim 10  wherein the substantially U-shaped channel includes:
 a first portion that receives sound from the front volume and is positioned adjacent a perimeter of the diaphragm; 
 a second portion that receives sound from the first portion and is oriented transverse to the first portion; 
 a third portion that directs sound received from the second portion to the sound port and is coupled to a distal end of the second portion. 
 
     
     
       12. The audio module of  claim 10  wherein a portion of the substantially U-shaped channel is formed by a channel cover that is attached to the frame. 
     
     
       13. The audio module of  claim 10  wherein the panel of acoustic mesh is oriented at an angle with respect to a plane of the diaphragm. 
     
     
       14. The audio module of  claim 10  wherein the panel of acoustic mesh is insert-molded within the frame. 
     
     
       15. An electronic device comprising:
 a device enclosure; 
 a display assembly coupled to the device enclosure, the combination thereof defining an interior volume, wherein the display assembly includes a touch sensitive layer and a force sensitive layer; and 
 an audio module disposed within the interior volume and comprising: 
 (1) a driver assembly including:
 a diaphragm defining a speaker plane; and 
 a voice coil attached to the diaphragm and positioned adjacent one or more magnets; and 
 
 (2) an audio module enclosure surrounding the driver assembly and defining:
 a front volume coupled to a speaker opening formed in the device enclosure; 
 a back volume positioned on the first side of the speaker plane and on a second side of the speaker plane; and 
 a resonant cavity coupled to the front volume via a resonant cavity port and separated from the back volume by a resonant cavity cover. 
 
 
     
     
       16. The electronic device of  claim 15  further comprising a top flux plate in contact with a top surface of the one or more magnets and a bottom flux plate in contact with a bottom surface of the one or more magnets. 
     
     
       17. The audio module of  claim 15  further comprising a substantially U-shaped channel that couples the front volume to the speaker opening. 
     
     
       18. The electronic device of  claim 17  wherein a panel of acoustic mesh is positioned within the substantially U-shaped channel and is oriented at an angle with respect to the speaker plane. 
     
     
       19. The electronic device of  claim 15  wherein the back volume is further defined by a frame, the diaphragm and a rear cover attached to the frame. 
     
     
       20. The electronic device of  claim 15  further comprising a barometric vent coupling the front volume to the back volume.

Description:
CROSS-REFERENCES TO OTHER APPLICATIONS 
     This application claims priority to U.S. provisional patent application Ser. No. 62/398,065, for “CLOSED AUDIO MODULE IN AN ELECTRONIC DEVICE” filed on Sep. 22, 2016 which is hereby incorporated by reference in entirety for all purposes. 
    
    
     FIELD 
     The following description relates to an electronic device. In particular, the following relates to a portable electronic device that includes a sealed audio module that is positioned within the electronic device and is configured to emit sound from an aperture disposed within an external housing of the electronic device. 
     BACKGROUND 
     An electronic device may include a touch sensitive display secured to an housing to form an enclosure that stores several internal components, such as a battery and a processor circuit. The electronic device can also include one or more speakers designed to emit audible sound. The one or more speakers may be negatively affected by pressure fluctuations within the electronic device that are caused by a user pressing on the touch sensitive display. 
     SUMMARY 
     Some embodiments of the disclosure pertain to an audio module for an electronic device that is unaffected by pressure fluctuations within the electronic device that could be caused, for example, by pressure against a touch screen of the electronic device. Further embodiments can include features that enable the audio module to be positioned within an electronic device having a relatively thin profile. In some embodiments a portion of the back volume of the acoustic module can be positioned in front of the speaker plane to more effectively utilize available space within the electronic device. Various embodiments can include a U-shaped channel that enables the sound port of the acoustic module to be positioned away from the diaphragm. Some embodiments include a resonant cavity that can be positioned within a portion of the back volume and employed to compensate for any negative effects on the acoustic performance due to the U-shaped channel. 
     In some embodiments an audio module for an electronic device comprises a driver assembly comprising a diaphragm defining a speaker plane, a voice coil attached to the diaphragm and positioned adjacent one or more magnets, and an enclosure surrounding the driver assembly. The enclosure defines a front volume positioned on a first side of the speaker plane and coupled to a sound port, a back volume positioned on the first side of the speaker plane and on a second side of the speaker plane, and a resonant cavity coupled to the front volume via a resonant cavity port and separated from the back volume by a resonant cavity cover. 
     In some embodiments a first portion of the resonant cavity is positioned on the first side of the speaker plane and a second portion of the resonant cavity is positioned on the second side of the speaker plane. In various embodiments the back volume is further defined by a frame, the diaphragm and a rear cover attached to the frame. In some embodiments the driver assembly includes a bottom flux plate that forms a portion of the rear cover. In various embodiments a substantially U-shaped channel couples the front volume to the sound port. 
     In some embodiments the audio module further comprises a panel of acoustic mesh positioned within the substantially U-shaped channel and partially embedded within one or more walls that define the substantially U-shaped channel. In various embodiments the panel of acoustic mesh is oriented at an angle with respect to the speaker plane. 
     In some embodiments the resonant cavity is sized to resonate at a frequency that extends a bandwidth of the audio module. In various embodiments the audio module further comprises a barometric vent coupling the front volume to the back volume. 
     In some embodiments an audio module for an electronic device comprises a frame, a driver assembly disposed within the audio module and including a diaphragm positioned within a speaker opening in the frame and a front cover attached to the frame and positioned parallel to and spaced apart from the diaphragm in a first direction, wherein the front cover, the diaphragm and the frame define a front volume. A front volume aperture is positioned transverse to the diaphragm such that sound from the diaphragm exits the front volume in a direction parallel to the diaphragm. A rear cover is attached to the frame and positioned parallel to and spaced apart from the diaphragm in a second direction that is opposite the first direction. A substantially U-shaped channel couples acoustic energy from the front volume aperture to a sound port defined by the frame. A panel of acoustic mesh is positioned within the substantially U-shaped channel and has a perimeter embedded within a portion of the frame. 
     In some embodiments the substantially U-shaped channel includes a first portion that receives sound from the front volume and is positioned adjacent a perimeter of the diaphragm, a second portion that receives sound from the first portion and is oriented transverse to the first portion and a third portion that directs sound received from the second portion to the sound port and is coupled to a distal end of the second portion. In various embodiments a portion of the substantially U-shaped channel is formed by a channel cover that is attached to the frame. 
     In some embodiments the panel of acoustic mesh is oriented at an angle with respect to a plane of the diaphragm. In various embodiments the panel of acoustic mesh is insert-molded within the frame. 
     In some embodiments an electronic device comprises a device enclosure, a display assembly coupled to the device enclosure, the combination thereof defining an interior volume and wherein the display assembly includes a touch sensitive layer and a force sensitive layer. An audio module is disposed within the interior volume and comprises (1) a driver assembly including a diaphragm defining a speaker plane, and a voice coil attached to the diaphragm and positioned adjacent one or more magnets. The audio module further comprises (2) an audio module enclosure surrounding the driver assembly and defining a front volume coupled to a speaker opening formed in the device enclosure, a back volume positioned on the first side of the speaker plane and on a second side of the speaker plane, and a resonant cavity coupled to the front volume via a resonant cavity port and separated from the back volume by a resonant cavity cover. 
     In some embodiments the electronic device further comprises a top flux plate in contact with a top surface of the one or more magnets and a bottom flux plate in contact with a bottom surface of the one or more magnets. In various embodiments the audio module further comprises a substantially U-shaped channel that couples the front volume to the speaker opening. 
     In some embodiments a panel of acoustic mesh is positioned within the substantially U-shaped channel and is oriented at an angle with respect to the speaker plane. In various embodiments the back volume is further defined by a frame, the diaphragm and a rear cover attached to the frame. In some embodiments the electronic device further comprises a barometric vent coupling the front volume to the back volume. 
     Other embodiments of the disclosure pertain to different enhancements over traditional devices. For example, in one embodiment and electronic device may include a protective layer formed from a transparent material. The electronic device may further include a display assembly. The display assembly may include a touch sensitive layer that detects a touch input to the protective layer. The display assembly may further include a force sensitive layer that detects an amount of force from the touch input. The display assembly may further include a display between touch sensitive layer and the force sensitive layer. In some embodiments, the display at least partially bends around the force sensitive layer defining a bent region. The electronic device may further include a frame that carries the protective layer. The frame may include a notch that at least partially receives the display at the bent region. 
     In another aspect, an electronic device is described. The electronic device may include a protective layer formed from a non-metal material. The electronic device may further include an enclosure formed from a metal. The enclosure may include a support region that receives the outer protective layer. In some embodiments, the protective layer and the enclosure define an internal cavity. The electronic device may further include an operational component positioned in the internal cavity. The operational component may generate heat when performing an operation. The electronic device may further include a thermal distribution assembly secured with the enclosure and the protective layer. The thermal distribution assembly may draw the heat from the internal component and dispersing the heat to the enclosure. 
     In another aspect, an electronic device is described. The electronic device may include an enclosure defining an internal cavity. The electronic device may further include a circuit assembly disposed in the internal cavity. The circuit assembly may include a first circuit board that includes a first surface and a second surface opposite the first surface. The first surface may include a first operational component and the second surface may include a second operational component. The circuit assembly may further include a second circuit board electrically coupled with the first circuit board. The second circuit board may include a third surface that faces the second surface. Also, the third surface may include a third operational component. 
     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  illustrates a front isometric view of an embodiment of an electronic device, in accordance with some described embodiments; 
         FIG. 2  illustrates a rear isometric view of the electronic device shown in  FIG. 1 , further showing additional features of the electronic device; 
         FIG. 3  illustrates a partial exploded view of the electronic device shown in  FIG. 1 , showing various components of the electronic device; 
         FIG. 4  illustrates a partial exploded view of the electronic device shown in  FIG. 1 , further showing additional components of the electronic device; 
         FIG. 5  illustrates a cross sectional view of the electronic device shown in  FIG. 1 , taken along line A-A in  FIG. 1 ; 
         FIG. 6  illustrates a cross sectional view of an alternate embodiment of an electronic device, in accordance with some described embodiments; 
         FIG. 7  illustrates a cross sectional view of the electronic device shown in  FIG. 1 , taken along line B-B in  FIG. 1 ; 
         FIG. 8  illustrates a cross sectional view of an alternate embodiment of an electronic device, in accordance with some described embodiments; 
         FIG. 9  illustrates a cross sectional view of an electronic device in accordance with some described embodiments; 
         FIG. 10  illustrates an exploded view of the circuit assembly, in accordance with some described embodiments; 
         FIG. 11  illustrates a cross sectional view of the circuit assembly shown in  FIG. 10 , showing various internal components of the circuit assembly; 
         FIG. 12  illustrates an alternative embodiment of a circuit assembly, showing the circuit assembly modified for ingress protection; 
         FIG. 13  illustrates an alternate embodiment of a circuit assembly, showing the circuit assembly having a flexible circuit electrically coupled with the circuit boards of the circuit assembly, in accordance with some described embodiments; 
         FIG. 14  illustrates a cross sectional view of the circuit assembly shown in  FIG. 13 , showing the flexible circuit extending between the circuit boards; 
         FIG. 15  illustrates a cross sectional view of an alternate embodiment of a circuit assembly, showing internal components of the circuit assembly having corresponding geometries, in accordance with some described embodiments; 
         FIG. 16  illustrates a cross sectional view of an alternate embodiment of a circuit assembly, showing the circuit assembly having several solder masks used to support a circuit board, an accordance with some described embodiments; 
         FIG. 17A  illustrates a top plan view of an embodiment of an audio module, in accordance with embodiments described herein; 
         FIG. 17B  illustrates cross-sectional view A-A of the audio module illustrated in  FIG. 17A ; 
         FIG. 17C  illustrates cross-sectional view B-B of the audio module illustrated in  FIG. 17A ; 
         FIG. 17D  illustrates an isometric front view of a frame that forms a portion of the audio module illustrated in  FIG. 17A ; 
         FIG. 17E  illustrates an isometric back view of a frame that forms a portion of the audio module illustrated in  FIG. 17A ; 
         FIG. 17F  illustrates an isometric view of a magnetic assembly that can be used in the audio module illustrated in  FIG. 17A ; 
         FIG. 17G  illustrates an isometric view of a second portion of a rear cover that forms a portion of an enclosure of the audio module illustrated in  FIG. 17A ; 
         FIG. 18  illustrates an isometric view of an alternative embodiment of a magnet assembly that can be used in the audio module illustrated in  FIG. 17A ; 
         FIG. 19  illustrates an exploded view of a thermal distribution assembly, in accordance with some described embodiments; 
         FIG. 20  illustrates a side view of an embodiment of the electronic device, showing the thermal distribution assembly positioned in the electronic device; 
         FIG. 21  illustrates a side view of an alternative embodiment of a thermal distribution assembly, in accordance with some described embodiments; 
         FIG. 22  illustrates an isometric view of the thermal distribution assembly shown in  FIG. 21 , showing the thermal distribution assembly modified to receive a component; 
         FIG. 23  illustrates an isometric view of an alternative embodiment of a thermal distribution assembly, in accordance with some described embodiments; and 
         FIG. 24  illustrates a flowchart showing a method for forming an electronic device, in accordance with some 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. 
     In some embodiments an audio module is disclosed that can be used within an electronic device to generate sound for a user. In one example the audio module is a receiver for a cellular telephone and can include features for enhanced audio performance as described in more detail below. 
     In some embodiments the audio module is unaffected by pressure fluctuations within the electronic device that could be caused, for example, by pressure against a touch screen of the electronic device. More specifically, when a force is applied to the touch screen the touch screen deflects causing an internal volume of the electronic device to be momentarily reduced which in turn results in an increase of the air pressure within the electronic device. Since the audio module is located within the electronic device it is subjected to the increase in air pressure. To protect the audio module from altering its acoustic output in response to the momentary increase in air pressure the audio module can include a completely sealed enclosure that has a sound port that is sealed to the enclosure of the electronic device so the only opening the audio module has is to the external environment outside of the electronic device. 
     Further embodiments can include features that enable the audio module to be positioned within an electronic device having a relatively thin profile. In some embodiments a portion of the back volume of the acoustic module can be positioned in front of the speaker plane to more effectively utilize available space within the electronic device. Various embodiments can include a U-shaped channel that enables the sound port of the acoustic module to be positioned away from the diaphragm. More specifically, the U-shaped channel can function as a sound channel that enables acoustic energy generated by the driver assembly to be ported to a location remote from the driver assembly and out of the electronic device enclosure. A resonant cavity can be positioned within a portion of the back volume and employed to compensate for any negative effects on the acoustic performance due to the U-shaped channel. Further details of the audio module and its various features for enhanced audio performed are described in more detail below. 
     In other embodiments, the disclosure relates to an electronic device. The electronic device may include several enhancements over traditional devices. For example, the electronic device may include an enclosure and a display that extends (approximately) to the enclosure, thereby maximizing the size of the display. The display may be part of a display assembly that further includes a touch sensitive layer and a force sensitive layer. In order to accommodate the increased display size, a border that surrounds the display may decrease in size. However, the reduced presence of the border may expose electrical and mechanical connections between the display and internal components within the enclosure. In order to hide these connections, the display assembly components may be electrically and mechanically coupled with their respective flexible circuits in different locations. For example, the touch sensitive layer and the display may electrically and mechanically couple with their flexible circuits at one location inside the electronic device, while the force sensitive layer electrically and mechanically couples with a flexible circuit at a different location away from the electrical and mechanical connections between the touch sensitive layer, the display, and their respective flexible circuits. Also, by routing the electrical and mechanical connection in different locations, the volume occupied by the display assembly is reduced, and the internal volume of the electronic device may be used by a different component(s) in the electronic device. 
     The electronic device may further include a circuit assembly designed to occupy less space in the electronic device. For example, the circuit assembly may be divided into a first circuit board stacked over a second circuit board, thereby reducing the footprint of the circuit assembly in two dimensions. Also, the aforementioned circuit boards may include operational components (such as integrated circuits or processor circuits) positioned on multiple, different surfaces. The operational components may perform an operation (or operations) such as executing instructions from a software application stored on a memory circuit. As an example, the first circuit board may include a first surface and a second surface opposite the first surface, with each surface having one or more operational components. Also, the circuit board assembly may include several interposers designed to route signals between the first and second circuit boards, such that the first and second circuit boards (as well as their respective operational component) are in communication with one another. 
     The electronic device may further include an internal power supply (battery). Due in part to the modifications to the display assembly and the circuit board assembly that create additional volume, the internal power supply may occupy at least some of the additional volume, thereby increasing the size of the internal power supply as well as the charge capacity of the internal power supply. Also, additional components, such as antennae and circuits, may be repositioned in the electronic device in order to increase the size of the internal power supply. 
     Also, in some instances, the enclosure may include a metal band coupled with a protective layer that covers the display assembly. The enclosure may further include an additional protective layer coupled with the metal band. The additional protective layer may include a glass material. When the circuit assembly generates heat, it may be necessary to remove the heat from the internal volume to avoid damage to a component (or components) in the electronic device. In this regard, the electronic device may include a thermal distribution assembly formed from several layers of metal, one of which may include a relatively high thermal conductivity. The thermal distribution assembly is designed to transfer the heat from the heat-generating component(s) to the metal band, where the heat can dissipate from the electronic device. 
     Also, when a user interacts with the display assembly, the force sensitive layer may determine an amount of force exerted on the display in order to generate a command in accordance with the amount of force. However, the force applied to the display (by way of the protective layer) may reduce the internal volume momentarily, and as a result, increase the internal air pressure. The increased internal pressure may affect other components, such as an audio module designed to generate acoustical energy. In order to shield the audio module from increased pressure, the receiver may include an enclosed back volume. In this manner, the audio module is unaffected from pressure changes in the electronic device as the enclosed back volume does not change based on pressure changes. 
     These and other embodiments are discussed below with reference to  FIGS. 1-29 . 
     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  illustrates a front isometric view of an embodiment of an electronic device  100 , in accordance with some described embodiments. In some embodiments, the electronic device  100  is a tablet computer device. In the embodiment shown in  FIG. 1 , the electronic device  100  is a mobile communication device, such as a smartphone. Accordingly, the electronic device  100  may enable wireless communication in the form of cellular network communication, Bluetooth communication (2.4 GHz), and/or wireless local area network (WLAN) communication (2.4 GHz to 5 GHz), as non-limiting examples. 
     As shown, the electronic device  100  may include a display assembly  102  (shown as a dotted line) designed to present visual information in the form of textual information, still images, and/or video information. Although not shown, the display assembly  102  may further include a touch sensitive layer designed to detect a touch input to the display assembly  102  in order to control an output of the display assembly  102 . Also, the display assembly  102  may further include a force sensitive layer designed to detect an amount of force exerted on the display assembly  102 . The determined amount of force may correspond to a particular input or command to the display assembly  102 . For example, different detected amounts of force may correspond to different or distinct commands. In order to protect the display assembly  102 , the electronic device  100  may include a first protective layer  104  that overlays the display assembly  102 . The first protective layer  104  may include a transparent material(s), including glass or sapphire, as non-limiting examples. 
     As shown, the first protective layer  104  may include openings that facilitate user interaction with the electronic device  100 . For example, the first protective layer  104  may include a first opening  106  and a second opening  108 . The electronic device  100  may include an image capture device (not shown) that captures an image (or images) through the first opening  106 . The electronic device  100  may further include an audio module (not shown) located near the second opening  108 , with the audio module generating acoustical energy in the form of audible sound, and emits the acoustical energy through the second opening  108 . 
     Also, the electronic device  100  may include a band  110  that defines an outer perimeter of the electronic device  100 . Generally, the band  110  includes a shape similar to that of a ring. Also, the band  110  may define multiple sidewalls and an opening to at least partially receive the first protective layer  104  and a second protective cover (not shown). In some embodiments, the band  110  includes a metal, such as aluminum. In this regard, the band  110  may provide a rigid support structure for the electronic device  100 . Also, when the band  110  is formed from a metal, the band  110  may be used to support wireless communication. For example, the band  110  may include a first part  112  that forms a U-shape design, as well as a second part  114  that also forms a U-shape design. The first part  112  and the second part  114  may each electrically couple to a radio circuit (not shown) in the electronic device  100  such that the first part  112  and the second part  114  each form at least part of an antenna for their respective radio circuits. For example, the first part  112  may electrically couple with a WLAN radio circuit, and the second part  114  may electrically couple with a cellular network radio circuit. 
     Also, the band  110  may further include a third part  116  and a fourth part  118 , with the third part  116  and the fourth part  118  separated from both the first part  112  and the second part  114  by split regions, or openings. For example, the band  110  may include a first split region  122  and a second split region  124  that combine to separate the third part  116  from the first part  112  and the second part  114 . Also, the band  110  may include a third split region  126  and a fourth split region  128  that combine to separate the fourth part  118  from the first part  112  and the second part  114 . The aforementioned split regions may be filled with a non-metal material, such as molded plastic, to provide a flush, co-planar surface with the various parts of the band  110 . Also, the first part  112 , the second part  114 , the third part  116 , and the fourth part  118  may each represent a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall, respectively. 
     The electronic device  100  may further include a first button  130  designed to generate an input when depressed. The input may generate an electrical signal received by a processor circuit (not shown) in the electronic device  100 , in order to alter the visual information presented on the display assembly  102 . As shown, the first button  130  is located along the third part  116 . However, other locations are possible. Also, although not shown, the electronic device  100  may include a switch designed to provide an additional user input function. 
     Also, the electronic device  100  may further include a data port  132  designed to receive and electrically couple with a cable assembly (not shown). The data port  132  may receive data/communication from the cable assembly, as well as electrical energy to charge an internal power supply (not shown) located in the electronic device  100 . Also, the electronic device  100  may include additional openings designed for various user interactions. For example, the electronic device  100  may include an audio module (not shown) located near openings  134  such that the openings  134  allow acoustical energy generated from the audio module to exit the electronic device  100 . Also, the electronic device  100  may further include a microphone (not shown) located near an opening  136 . The microphone may be positioned to receive acoustical energy through the opening  136 . 
       FIG. 2  illustrates a rear isometric view of the electronic device  100  shown in  FIG. 1 , further showing additional features of the electronic device  100 . As shown, the electronic device  100  may include a second protective layer  144  secured with the band  110 . The second protective layer  144  may combine with the band  110  to define an enclosure  155  that includes an internal cavity that receives several internal components, such as circuit boards, integrated circuits, internal power supply, as non-limiting examples. In this regard, the band  110  may include a first edge region (shown in  FIG. 1 ) that receives the first protective layer  104 , as well as a second edge region that receives the second protective layer  144 , with the first edge region and the second edge regions in opposite, or opposing, locations of the band  110 . 
     The second protective layer  144  may include materials, such as glass, sapphire, or plastic. Generally, the second protective layer  144  may include any material (or materials) that provides a rigid support, while also allowing radio frequency (“RF”) communication, generated from internal radio circuits (not shown) of the electronic device  100 , to permeate through the material(s) of the second protective layer  144 . In this manner, the electronic device  100  may be in wireless communication with other devices (not shown) by way of RF communication that is substantially uninhibited by the second protective layer  144 . 
     Also, the second protective layer  144  may include openings that facilitate user interaction with the electronic device  100 . For example, the second protective layer  144  may include a first opening  146  and a second opening  148 . The electronic device  100  may include an image capture device (not shown) that captures an image (or images) through the first opening  146 . The electronic device  100  may further include flash module (not shown) located near the second opening  148 , with the flash module generating light energy during an image capture event from the image capture device in order to enhance image quality of the image taken by the image capture device. 
     The electronic device  100  may further include a second button  150  designed to generate an input when depressed. The input may generate an electrical signal received by a processor circuit (not shown) in the electronic device  100 , in order to alter the visual information presented on the display assembly  102 . As shown, the second button  150  is located along the fourth part  118 . However, other locations are possible. 
       FIG. 3  illustrates a partial exploded view of the electronic device  100  shown in  FIG. 1 , showing various components of the electronic device  100 . As shown, the first protective layer  104  may overlay the display assembly  102 . Also, the first protective layer  104  may adhesively secure with the display assembly  102  by an adhesive layer (not shown). Further, in order to support the first protective layer  104  and facilitate assembly of the first protective layer  104  with the band  110  (shown in  FIG. 1 ), the electronic device  100  may include a frame  154  that secured with the first protective layer  104  by an adhesive layer (not shown). The frame  154  may be positioned at least partially between the first protective layer  104  and the band  110 . Accordingly, the frame  154  may include a size and shape in accordance with that of the first protective layer  104 . Also, the frame  154  may be formed from a polymeric material, such as plastic, and may also include a metal ring (not shown) that is partially embedded in the polymeric material during an insert molding operation. In this regard, the frame  154  may structurally support the first protective layer  104 , as well as one or more components of the display assembly  102 . This will be shown below. 
       FIG. 4  illustrates a partial exploded view of the electronic device  100  shown in  FIG. 1 , further showing additional components of the electronic device  100 . As shown, the band  110  and the second protective layer  144  may combine to provide an internal volume  152  for several internal components. For example, the electronic device  100  may include an internal power supply  160 , or battery, designed to distribute electrical current to operational components of the electronic device  100 . The internal power supply  160  may include a rechargeable battery designed to receive electrical current during a recharge. For example, the electronic device  100  may include an inductive receiver coil  162  designed to generate electrical current when exposed to an alternating magnetic field from an external device (not shown). As an alternative charging process to the data port  132  (shown in  FIG. 1 ), the inductive receiver coil  162  can supply the internal power supply  160  with electrical current in order to recharge the internal power supply  160 . Also, the non-metal material makeup of the second protective layer  144  allows the external magnetic field to pass through the second protective layer  144  and extend to and around the inductive receiver coil  162 . 
     The electronic device  100  may further include a circuit assembly  170  that includes multiple operational components. As shown, the circuit assembly  170  may include a first circuit board  172  and a second circuit board  174 , with the first circuit board  172  stacked over the second circuit board  174 . In this manner, the circuit assembly  170  can conserve space, in the x- and y-dimensions, in the internal volume  152 . The various features of the circuit assembly  170  will be discussed below. 
     The electronic device  100  may further include a first audio module  182  and/or a second audio module  184 , both of which are designed to generate acoustical energy in the form of audible sound. First and second audio modules  182 ,  184 , respectively, may each include an opening to emit acoustical energy that a user can hear. In some embodiments, at least some of the internal volume of first and second audio modules  182 ,  184 , respectively, is isolated from the internal volume  152  of the electronic device  100 . In this manner, when the internal volume  152  changes by, for example, depressing the first protective layer  104  (shown in  FIG. 4 ) to provide a touch input and/or a force input to the electronic device, the audio modules are not affected (acoustically) from the change in the internal volume  152 , and associated increased air pressure. This will be discussed in more detail below. 
     The electronic device  100  may further include a thermal distribution assembly  190 . The thermal distribution assembly  190  may include several layers of material. In some embodiments, the layers of material differ. For example, in some embodiments, the thermal distribution assembly  190  includes a first layer formed from a first type material (not labeled) surround by a second layer formed from a second type material (not labeled). The first type material may include a relatively high thermal conductivity, such as copper known to include a thermal conductivity of approximately 400 W/m*K (Watts per meter per Kelvin degree). Alternatively, the first type may include graphite known to include a thermal conductivity of approximately 170 W/m*K. Accordingly, the first type material is well suited to transfer thermal energy from one location to another location. The second type material may include a more robust material, such as stainless steel. The second type material may include a relatively lower thermal conductivity. However, the second type material may provide 1) a protective coating for the first type material, 2) structural support for the electronic device  100 , and/or 3) provide workable surface to secure a component (not shown) with the thermal distribution assembly  190  by, for example, a welding operation. The various layers of the thermal distribution assembly  190  will be further described below. 
     The thermal distribution assembly  190  can be designed to redirect or redistribute heat generated in the electronic device  100 . For example, the circuit assembly  170  may include operational components, such as integrated circuits, known to convert electrical energy (supplied by the internal power supply  160 ) into thermal energy during operation. The thermal distribution assembly  190  can be thermally coupled with the circuit assembly  170  by contact between the thermal distribution assembly  190  and the circuit assembly  170 , as a non-limiting example. Also, the thermal distribution assembly  190  may be thermally coupled with the band  110  such that thermal energy received by the thermal distribution assembly  190  from the circuit assembly  170  may at least partially transfer to the band  110 , which may also include metal. Accordingly, at least some thermal conductivity lost by using the second protective layer  144  is regained by using the thermal distribution assembly  190 . Also, the thermal distribution assembly  190  may include a size and shape in accordance with the second protective layer  144  such that thermal distribution assembly  190  covers, or at least substantially covers, a major (internal) surface of the second protective layer  144 . 
     Although not shown, the electronic device  100  may include additional components, such a haptic engine and internal antennae, as non-limiting examples. Also, although not shown, the electronic device  100  may include several flexible circuits that place the electronic components (e.g., display assembly  102 , circuit assembly  170 ) in electrical communication with one another as well as the internal power supply  160 . 
       FIG. 5  illustrates a cross sectional view of the electronic device  100  shown in  FIG. 1 , taken along line A-A in  FIG. 1 . As shown, the display assembly  102  may include a touch sensitive layer  202  designed to receive a touch input, a display layer  204  designed to present visual information, and a force sensitive layer  206  designed to detect an amount of force applied exerted on the display layer  204  by way of exerting a force on at least one of the first protective layer  104 , the touch sensitive layer  202 , and the display layer  204 . Also, although not shown, the display assembly  102  may include adhesive layers to adhesively secure the touch sensitive layer  202  with the display layer  204 , and to adhesively secure the display layer  204  with the force sensitive layer  206 . 
     The touch sensitive layer  202  is designed to receive a touch input when, for example, a user (not shown) depresses the first protective layer  104 . The touch sensitive layer  202  may include capacitive touch-sensitive technology. For example, the touch sensitive layer  202  may include a layer of capacitive material that holds an electrical charge. In this regard, by touching the screen, the amount of charge changes at a specific point of contact corresponding to a location of the user touch input, for example. The touch input can be relayed from the touch sensitive layer  202  to the circuit assembly  170  (shown in  FIG. 4 ) by a first flexible circuit  212  electrically and mechanically coupled with the touch sensitive layer  202 . As shown, the first flexible circuit  212  may bend or curve around the touch sensitive layer  202  and the display layer  204 . 
     In some embodiments, the display layer  204  includes a liquid crystal display (“LCD”) that relies upon backlighting to present the visual information. In the embodiment shown in  FIG. 5 , the display layer  204  includes an organic light emitted diode (“OLED”) display. The display layer  204 , when including an OLED display, is designed to illuminate (using electrical current from the internal power supply  160 ) individual pixels, when needed, in order to illuminate display layer  204 . When the display layer  204  includes OLED technology, the display layer  204  may include a reduced form factor as compared to an LCD display. In this regard, the display assembly  102  may include a smaller footprint, thereby create more space for other components such as the internal power supply  160  (shown in  FIG. 4 ). Furthermore, when the display layer  204  includes OLED technology, the display layer  204  can curve or bend without causing damage to the display layer  204 . For example, as shown in  FIG. 5 , the display layer  204  includes a 180-degree bend, or approximately 180-degree bend. As shown, the display layer  204  may be bend or curve around the force sensitive layer  206 , and electrically and mechanically couple with a second flexible circuit  214  that electrically couples with the circuit assembly  170  (shown in  FIG. 4 ) to place the display layer  204  in communication with the circuit assembly  170 . Also, the display layer  204  may include an active matrix organic light emitting diode (“AMOLED”) display. 
     The force sensitive layer  206  may operate by determine an amount of force or pressure is applied to the first protective layer  104 , the touch sensitive layer  202 , and/or the display layer  204 . In this regard, the force sensitive layer  206  may distinguish between different levels of force applied to the electronic device  100  by way of, for example, a force applied to the first protective layer  104 . The different levels of force may correspond to different user inputs. The force sensitive layer  206  may include multiple capacitor plates, with one plate of the capacitor plate pairs having an electrical charge. When a force to the electronic device  100 , the distance between one least one pair of capacitor plates changes, causing a change in capacitance. The amount of change in capacitance corresponds to an amount of force exerted on the electronic device  100 . 
     The frame  154  may include design considerations that accommodate for the display assembly  102 . For example, the frame  154  may include a notch  156 , or undercut region, designed to at least partially receive the first flexible circuit  212  and/or the display layer  204 . As shown in  FIG. 5 , the notch  156  includes a size and shape to receive both a bent region of the display layer  204  as well the first flexible circuit  212  in a portion (of the first flexible circuit  212 ) that is curved or bent. While the notch  156  includes a curvature generally corresponding to that of the first flexible circuit  212  and the display layer  204 , other shapes, including straight edges, are possible for the notch  156 . Also, the notch  156  may be formed during a molding operation of the frame  154 . Alternatively, the notch  156  may be formed subsequent to a molding operation by, for example, a cutting operation. 
     Also, the frame  154  is adhesively secured with the first protective layer  104  and the second part  114  (of the band  110 , shown in  FIG. 1 ) by adhesive layers (not labeled). The frame  154  may include a ring  158  partially embedded in the frame  154 . In some embodiments, the ring  158  includes a metal ring that may include a continuous metal. However, the ring  158  may also be discontinuous, and accordingly, may be selectively embedded in the frame  154 . As shown, the ring  158  may extend along the frame  154  to support the display assembly  102  and the first protective layer  104 . Also, the first flexible circuit  212  may adhesively secure with the ring  158  by an adhesive layer (not shown). 
       FIG. 5  further shows the some components of the display assembly  102  are coupled with the flexible circuits at one location while other components are not. For example, the touch sensitive layer  202  and the display layer  204  are electrically and mechanically coupled with the first flexible circuit  212  and the second flexible circuit  214 , respectively, at a location proximate to the second part  114  (defined by a U-shape configuration), while the force sensitive layer  206  is not. Alternatively, the touch sensitive layer  202  and the display layer  204  are electrically and mechanically coupled with the first flexible circuit  212  and the second flexible circuit  214 , respectively, at a location proximate to the notch  156  in the frame  154 , while the force sensitive layer  206  is not. The electrical and mechanical coupling between the force sensitive layer  206  and a flexible circuit will be shown below. 
       FIG. 6  illustrates a cross sectional view of an alternate embodiment of an electronic device  250 , in accordance with some described embodiments. The electronic device  250  may include any feature or component previously described for an electronic device. For example, the electronic device  250  may include a display assembly  252  that includes a touch sensitive layer  262 , a display  264 , and a force sensitive layer  266 . However, as shown in  FIG. 6 , the display  264  may include a substantially flat configuration throughout the display  264 , with a flexible circuit  274  bending around the force sensitive layer  266  to electrically and mechanically couple with the display  264 . 
       FIG. 7  illustrates a cross sectional view of the electronic device  100  shown in  FIG. 1 , taken along line B-B in  FIG. 1 . As shown, the force sensitive layer  206  is electrically and mechanically coupled with a third flexible circuit  216  that electrically couples with the circuit assembly  170  (shown in  FIG. 4 ) to place the force sensitive layer  206  in communication with the circuit assembly  170 . Also, the third flexible circuit  216  may adhesively secure with the ring  158  by an adhesive layer (not labeled). 
     As shown in  FIG. 7 , only the force sensitive layer  206  includes an electrical and mechanical connection with a flexible circuit. In other words, the electrical and mechanical connection between the force sensitive layer  206  and the third flexible circuit  216  is in a different location of the electronic device  100 , as compared to the electrical and mechanical connections between the touch sensitive layer  202  and the first flexible circuit  212  (shown in  FIG. 5 ), and the electrical and mechanical connections between the display layer  204  and the second flexible circuit  214  (shown in  FIG. 5 ). Further, the electrical and mechanical connection between the force sensitive layer  206  and the third flexible circuit  216  is proximate to the third part  116 , which is defines in part a sidewall that is perpendicular, or approximately, perpendicular to a sidewall defined by the second part  114  (shown in  FIG. 5 ). As a result, the frame  154  may not require a notch  156 , or undercut, shown in  FIG. 5 , to accommodate the display layer  204  and the first flexible circuit  212  (shown in  FIG. 5 ). The additional material of the frame  154  may allow for additional structural rigidity of the frame  154 . 
       FIG. 8  illustrates a cross sectional view of an alternate embodiment of an electronic device  300 , in accordance with some described embodiments. The electronic device  300  may include any feature or component previously described for an electronic device. For example, the electronic device  300  may include a first protective layer  304  secured with a display assembly  302 , and a frame  354  that carries the first protective layer  304 . However, the first protective layer  304  may include an extension  306  that at least partially surrounds the first protective layer  304  in a circumferential manner. In order to accommodate the extension  306 , the frame  354  may include a notch  366  that receives the extension  306 . The extension  306  provides the first protective layer  304  with an additional profile to which the first protective layer  304  adhesively bonds with the frame  354 . For example, as shown in  FIG. 8 , the first protective layer  304  is adhesively secured with the frame  354  by an adhesive layer  362  that extends through a region defined in part by an interface region between the frame  354  and the first protective layer  304 , including the extension  306 . Also, the distance or gap between the frame  354  and the first protective layer  304  (including the extension  306 ) may cause the adhesive layer  362  to extend through the interface region by capillary forces. As a result, the frame  354  is adhesively secured with the first protective layer  304  by multiple (perpendicular) surfaces in order to form a stronger adhesive bond. 
       FIG. 9  illustrates a cross sectional view of an alternate embodiment of an electronic device  800 , in accordance with some described embodiments. As shown, the internal power supply  860  may pass over the first internal component  872 , while also having a channel  862  that includes a size and shape to receive the flexible circuit  864 . Although not shown, the channel  862  may include a size and shape to receive two or more flexible circuits in order to electrically couple additional internal components (not shown) with a circuit assembly. Also, the channel  862  may include a size and shape such that the flexible circuit  864  (or additional flexible circuits) does/do not extend behind the internal power supply  860  in the z-dimension. 
       FIG. 10  illustrates an exploded view of the circuit assembly  170 , in accordance with some described embodiments. As shown, the circuit assembly  170  may include a first circuit board  172  and a second circuit board  174 . In some embodiments, the first circuit board  172  and the second circuit board  174  each include a printed circuit board. Also, in order to conserve space in the electronic device  100  (shown in  FIG. 1 ), the first circuit board  172  may be secured with, and positioned over, the second circuit board  174  in a stacked configuration. The additional space provided by stacking the circuit boards may provide additional space in the electronic device  100  for other components, such as the internal power supply  160  (shown in  FIG. 4 ). Also, the additional space provided by the display layer  204  (shown in  FIG. 5 ) may allow for the stacked configuration of the circuit boards. Moreover, in some embodiments (not shown), the circuit assembly  170  includes three or more circuit boards in a stacked configuration. 
     The first circuit board  172  and/or the second circuit board  174  may include several operational components, including integrated circuits (processor circuits, memory circuits) and transistors, as non-limiting examples. Furthermore, the circuit boards may include operational components on multiple surfaces. For example, the first circuit board  172  may include a first surface  902  and a second surface  904  opposite the first surface  902 , with the first surface  902  having a first operational component  912  and the second surface having a second operational component  914  (shown as a dotted line). As shown in  FIG. 10 , both the first surface  902  and the second surface  904  may include additional operational components. Also, it should be noted that the operational components on the first circuit board  172  are in electrical communication with each other. The communication means may include, for example, at least one via extending through the first circuit board  172 . 
     The second circuit board  174  may include a first surface  906  that includes several operational components, such as an operational component  916 . The second circuit board  174  also includes a second surface  908  opposite the first surface  906 . In some embodiments, the second surface  908  includes operational components in electrical communication with the operational components located on the first surface  906 . 
     The first circuit board  172  may mechanically connect with the second circuit board  174  by several standoffs connected with rivets. For example, as shown in  FIG. 10 , the second circuit board  174  includes a first standoff  922  designed to connect with a first rivet  924  located on the first circuit board  172 . The remaining standoffs and rivets (not labeled) may connect with one another. The standoffs may maintain a desired distance between the first circuit board  172  and the second circuit board  174  such that components on the second surface  904  of the first circuit board  172  do not interfere with components on the first surface  906  of the second circuit board  174 , and vice versa. Also, the positioning of the standoffs and the rivets may be reversed such that the first circuit board  172  includes the standoffs and the second circuit board  174  includes the rivets. 
     In order to electrically couple the first circuit board  172  with the second circuit board  174 , several interposers may be used to route electrical signals between the first circuit board  172  and the second circuit board  174 . For example, as shown in  FIG. 12 , the second circuit board  174  may include several interposers, such as an interposer  932 , electrically with the second circuit board  174  by a soldering operation. Several additional interposers (not labeled) are shown. Also, although not shown, the second circuit board  174  may include several metal traces that electrically couple the interposers with one or more operational components on the second circuit board  174 . Also, each of the interposers may electrically couple with one or more metal traces (not shown) on the second surface  904  of the first circuit board  172 . 
     The circuit assembly  170  may include several shielding features that may shield the components of the circuit assembly  170  from electromagnetic interference (“EMI”), and also may shield components of the electronic device  100  (shown in  FIG. 1 ) that are external to the circuit assembly  170  from EMI generated by one or more components of the circuit assembly  170 . For example, the circuit assembly  170  may include a first shielding element  942  that covers components located on the first surface  902  of the first circuit board  172 . The first shielding element  942  may include a metal-based material designed to form an EMI shield. 
     The circuit assembly  170  may further include a second shielding element  944  designed to an EMI shield for operational components located on the second surface  904  of the first circuit board  172  and the first surface  906  of the second circuit board  174 . The second shielding element  944  may include a metal, such as copper or brass. The second shielding element  944  may secure with the first circuit board  172  and the second circuit board  174  by several solder joints disposed on each board. For example,  FIG. 12  shows the second circuit board  174  having several solder joints, such as a first solder joint  950 , positioned around an outer perimeter of the second circuit board  174 . The first circuit board  172  may also include solder joints (not shown) in locations corresponding to the solder joints on the second circuit board  174 . In some embodiments, the second shielding element  944  includes several discontinuous structural elements. In the embodiment shown in  FIG. 10 , the second shielding element  944  includes a continuous structural component designed to extend around an outer perimeter of the circuit assembly  170 . 
     Also, the circuit assembly  170  may further include a third shielding element  946  positioned on the second surface  908  of the second circuit board  174 . The third shielding element  946  may include metal traces throughout the second surface  908 . In addition to forming an EMI shield, the third shielding element  946  may define at least part of an electrical ground path for the circuit assembly  170 . 
       FIG. 11  illustrates a cross sectional view of the circuit assembly  170  shown in  FIG. 10 , showing various internal components of the circuit assembly  170 . As shown, the first circuit board  172  may be separated from the second circuit board  174  by a standoff  926 . Further, in order to mechanically couple the first circuit board  172  with the second circuit board  174 , the standoff  926  can be mechanically coupled with the a rivet  928 . 
     The first circuit board  172  may include a via  918  formed from a metal to provide an electrical connect between the first operational component  912  and the second operational component  914 . Also, the first circuit by  172  may be in electrical communication with the second circuit board  174  by way of an interposer  934 . As shown, the interposer  934  may electrically and mechanically connect with a first solder joint  962  located on the first circuit board  172 , and may also electrically and mechanically connect with a second solder joint  964  located on the second circuit board  174 . In addition to the interposer  934 , several additional interposers (not shown) may be used to carry signals between the circuit boards. The first circuit board  172  may include a first metal trace  972  electrically connected with the second operational component  914  as well as the via  918 , and the second circuit board  174  may include a first metal trace  974  electrically connected with a third operational component  920  located on the second circuit board  174 . In this manner, the third operational component  920  may electrically communicate with the second operational component  914  and/or the third operational component  920 . The circuit assembly  170  may use several additional metal traces, operational components, and solder joints to provide additional electrical communication pathways. 
       FIG. 12  illustrates an alternative embodiment of a circuit assembly  1070 , showing the circuit assembly  1070  modified for ingress protection. The circuit assembly  1070  may include any components and features previously described for a circuit assembly. However, as shown in  FIG. 12 , the circuit assembly  1070  may include a potting material  1090  positioned between a first circuit board  1072  and a second circuit board  1074  of the circuit assembly  1070 . The potting material  1090  may include resin that cures to form a water-resistant material for the various operational components of the circuit assembly  1070 . In this regard, the potting material  1090  may prevent damage to the circuit assembly  1070 , and in particular to an operational component  1014 , otherwise caused by liquid ingress. Further, the potting material  1090  may extend to a first shielding element  1042  and a second shielding element  1044  of the circuit assembly  1070 , in order to prevent corrosion to components, such as a standoff  1026 . Although not shown, the potting material  1090  may be applied to the circuit assembly  170  (shown in  FIG. 11 ). 
       FIG. 13  illustrates an alternate embodiment of a circuit assembly  1170 , showing the circuit assembly  1170  having a flexible circuit  1102  electrically coupled with the circuit boards of the circuit assembly, in accordance with some described embodiments. The circuit assembly  1170  may include any components and/or features previously described for a circuit assembly. For example, as shown, the circuit assembly  1170  may include a first circuit board  1172  and a second circuit board  1174 . The circuit assembly  1170  may further include a first shielding element  1142  disposed over the first circuit board  1172  and at least some of its components. The circuit assembly  1170  may further include a second shielding element  1144  covering a gap between the first circuit board  1172  and the second circuit board  1174 . The circuit assembly  1170  may further include a third shielding element  1146  disposed over the second circuit board  1174 . However, rather than using interposers for electrical communication, the circuit assembly  1170  relies upon the flexible circuit  1102  in communication with both the first circuit board  1172  and the second circuit board  1174 . 
     The flexible circuit  1102  may electrically and mechanically couple with the first circuit board  1172  and the second circuit board  1174  by a hot bar soldering operation. A thermode (not shown) may be used as a “hot bar” that is heated in order to supply thermal energy to the flexible circuit  1102  and to soldering elements (not shown), resulting in an electro-mechanical connection. It should be noted that multiple hot bar soldering operations may be used to couple the flexible circuit  1102  with the first circuit board  1172  and the second circuit board  1174 . 
       FIG. 14  illustrates a cross sectional view of the circuit assembly  1170  shown in  FIG. 13 , taken along line D-D, showing the flexible circuit  1102  extending between the circuit boards. As shown, the flexible circuit  1102  may electromechanically couple with a first solder joint  1112  and a second solder joint  1114 , located on the first circuit board  1172  and the second circuit board  1174 , respectively. Also, the first solder joint  1112  may electrically couple with a first metal trace  1122  on the first circuit board  1172 , and the second solder joint  1114  may electrically couple with a second metal trace  1124  on the second circuit board  1174 . In this regard, the flexible circuit  1102  may electrically couple with several operational components (not shown), some of which are electrically coupled with the first metal trace  1122  and some of which are electrically coupled with the second metal trace  1124 . 
       FIG. 15  illustrates a cross sectional view of an alternate embodiment of a circuit assembly  1270 , showing internal components of the circuit assembly  1270  having corresponding geometries, in accordance with some described embodiments. The circuit assembly  1270  may include any components and/or features previously described for a circuit assembly. For example, the circuit assembly  1270  may include a first circuit board  1272  and a second circuit board  1274 . The first circuit board  1272  may include a first surface  1202  having a first operational component  1212  and a second surface  1204  (opposite the first surface  1202 ) having a second operational component  1214 . Further, the second circuit board  1274  may include a third operational component  1216  located on a first surface  1206  of the second circuit board  1274 . 
     However, the second operational component  1214  and the third operational component  1216  may be in a nested configuration. For example, as shown in  FIG. 15 , the third operational component  1216  may at least partially extend into a recess of the second operational component  1214 . This may allow for a reduce dimension of the circuit assembly  1270 , thereby reducing the overall space occupied by the circuit assembly  1270  in an electronic device (not shown). 
       FIG. 16  illustrates a cross sectional view of an alternate embodiment of a circuit assembly, showing the circuit assembly having several solder masks used to support a circuit board, an accordance with some described embodiments. The circuit assembly  1370  may include any components and/or features previously described for a circuit assembly. For example, the circuit assembly  1370  may include a first circuit board  1372  and a second circuit board  1374 . Further, the first circuit board  1372  and the second circuit board  1374  may include several solder joints (not labeled), with an interposer electrically coupled with a solder joint from the first circuit board  1372  and with a solder joint from the second circuit board  1374 . 
     In order to prevent oxidation of the solder joints and/or to prevent solder “bridges” from forming between adjacent solder joints during a soldering operation, the circuit assembly  1370  may include several soldering masks. For example, the circuit assembly  1370  may include a first solder mask  1322  between a first interposer  1302  and a second interposer  1304 , and a second solder mask  1324  between the second interposer  1304  and a third interposer  1306 . Based on their positions, the first solder mask  1322  may prevent a solder bridge between the first interposer  1302  and the second interposer  1304 , and the second solder mask  1324  may prevent a solder bridge between the second interposer  1304  and the third interposer  1306 . Moreover, the first solder mask  1322  and the second solder mask  1324  may provide a support structure, in places of bosses (previously described), that maintain a desired distance or separate between the first circuit board  1372  and the second circuit board  1374 . Further, the first circuit board  1372  may clamp onto the first solder mask  1322  and the second solder mask  1324 , and the first circuit board  1372  is maintained with the second circuit board  1374 . The interposers, solder joints, and solder masks may be representative of several additional interposers, solder joints, and solder masks, respectively. 
     Audio Module 
       FIG. 17A  illustrates a top plan view of an embodiment of an audio module  2200 , in accordance with some embodiments described herein. Audio module  2200  can be representative of first audio module  182  (shown in  FIG. 4 ) and/or second audio module  184  employed in electronic device  100 . More specifically, in some embodiments audio module  2200  can be used as a receiver module designed to generate audible sound for a receiver portion of a cellular telephone such as electronic device  100  (see  FIG. 1 ) and can include features for fitting within a low profile electronic device. 
     For example, some embodiments of the disclosure pertain to an audio module for an electronic device that is not affected by pressure fluctuations within the electronic device that could be caused, for example, by pressure against a touch screen of the electronic device. More specifically, when a force is applied to the touch screen the touch screen deflects causing an internal volume of the electronic device to be momentarily reduced which in turn results in an increase of the air pressure within the electronic device. Since the audio module is located within the electronic device it is subjected to the increase in air pressure. To protect the audio module from altering its acoustic output in response to the momentary increase in air pressure the audio module can include a completely sealed enclosure that has a sound port that is sealed to the enclosure of the electronic device so the only opening the audio module has is to the external environment outside of the electronic device. 
     Further embodiments can include features that enable the audio module to be positioned within an electronic device having a relatively thin profile. In some embodiments a portion of the back volume of the acoustic module can be positioned in front of the speaker plane to more effectively utilize available space within the electronic device. Various embodiments can include a U-shaped channel that enables the sound port of the acoustic module to be positioned away from the diaphragm. More specifically, the U-shaped channel can function as a sound channel that enables acoustic energy generated by the driver assembly to be ported to a location remote from the driver assembly and out of the electronic device enclosure. A resonant cavity can be positioned within a portion of the back volume, but separated from the back volume, and employed to compensate for any negative effects on the acoustic performance due to the U-shaped channel. Further details of audio module and its various features for enhanced audio performed are described in more detail below. 
     As shown in  FIG. 17A , audio module  2200  includes an enclosure  2201  surrounding a driver assembly  2202  (hidden in  FIG. 17A ) coupled to a sound port  2203 . Sound port  2203  can be equipped with one or more gaskets  2206  to seal enclosure  2201  to a housing of an electronic device within which the audio module is located such that audible sound can be generated by driver assembly  2202  and heard outside of the electronic device. For example, audio module  2200  can be secured within electronic device  100  (see  FIG. 1 ) and sound port  2203  can be sealed to enclosure  155  (see  FIG. 2 ) such that audible sound can be discharged from second opening  108  and heard by a user. As further illustrated in  FIG. 17A , enclosure  2201  can include one or more mounting tabs  2204  for securing audio module  2200  to an electronic device, and a plurality of electrical connections  2205  for coupling audio signals to driver assembly  2202 . 
       FIG. 17B  illustrates cross-sectional view A-A of audio module  2200  illustrated in  FIG. 17A . As shown in  FIG. 17B , audio module  2200  includes enclosure  2201  that includes a frame  2207  and a plurality of covers that are attached to the frame, as described in more detail below. Driver assembly  2202  is positioned within enclosure  2201  and includes a diaphragm  2208  positioned within a speaker opening  2209  in frame  2207 . Driver assembly  2202  further includes a voice coil  2210  that is attached to diaphragm  2208  and positioned adjacent a magnet assembly  2211 . Magnet assembly  2211  includes one or more permanent magnets  2212  positioned between a top flux plate  2213  and a bottom flux plate  2214 . Diaphragm  2208  is held in place within speaker opening  2209  by a flexible suspension ring  2215  attached to frame  2207  with a seal  2216 . 
     Voice coil  2210  includes one or more wire windings that are terminated to plurality of electrical connections  2205  (see  FIG. 17A ). Flexible suspension ring  2215  suspends diaphragm  2208  within speaker opening  2209  and is illustrated in an unbiased neutral position in  FIG. 17B  such that when a voltage is applied across one or more electrical connections  2205  (see  FIG. 17A ) a magnetic field is generated within voice coil  2210  and the diaphragm moves up or down within the speaker opening, creating acoustic energy that can be emitted from sound port  2203  (see  FIG. 17A ). 
     A front cover  2217  is attached to frame  2207  and is positioned parallel to and spaced apart from diaphragm  2208 . A front volume  2218  for driver assembly  2202  is defined by frame  2207 , front cover  2217  and diaphragm  2208  and is positioned substantially in front of a speaker plane  2228 . In some embodiments front cover  2217  can include a recessed region  2219  that is formed inward towards diaphragm  2208  to reduce a portion of front volume  2218  directly in front of diaphragm  2208  to reduce the acoustic load on driver assembly  2202  and assist in tuning the high frequency response of audio module  2200 . A rear cover  2220  is attached to frame  2207  and is positioned parallel to and spaced apart from diaphragm  2208 . In some embodiments a portion of rear cover  2220  includes bottom flux plate  2214 . 
     A back volume  2222  for driver assembly  2202  is defined by frame  2207  and rear cover  2220 . A substantial portion of back volume  2222  is positioned to the side of driver assembly  2202  such that a portion of back volume  2222  is in front of speaker plane  2228  (shown on the left side of  FIG. 17B ) and a portion of the back volume is positioned behind (e.g., on the opposite side of) the speaker plane (shown on the left side of  FIG. 17B  and elsewhere within the enclosure). 
     A resonant cavity  2223  is defined by frame  2207  and a resonant cavity cover  2224  that is attached to the frame. Resonant cavity  2223  is coupled to front volume  2218  with a resonant cavity port  2225  and resonant cavity cover  2224  separates the resonant cavity from back volume  2222 . In some embodiments resonant cavity  2223  can be configured to function as a Helmholtz resonator that is tuned to resonate at a particular frequency to adjust the frequency response of acoustic module  2200 , as discussed in more detail below. 
     In some embodiments a portion of back volume  2222  is filled with a material to increase the effective size of the back volume. In various embodiments the material can be a zeolite powder. An internal mesh  2226  can be used to restrain the material and/or adjust acoustic performance of the back volume. In various embodiments a neck  2221  can be added to rear cover  2220  and/or frame  2207  to reduce a cross-sectional area of back volume  2222  before it enters a region that is filled with the material. 
       FIG. 17C  illustrates cross-sectional view B-B of audio module  2200  illustrated in  FIG. 17A . As shown in  FIG. 17C , audio module  2200  includes a front volume aperture  2227  positioned transverse to diaphragm  2208  such that sound from the diaphragm exits front volume  2218  in a direction parallel to the diaphragm. After the sound passes through front volume aperture  2227  it enters a substantially U-shaped channel  2229  that is coupled between the front volume aperture and sound port  2203 . U-shaped channel  2229  includes a first portion  2230  that directs sound from front volume aperture  2227  in a direction away from front cover  2217  towards rear cover  2220 . A second portion  2231  of U-shaped channel  2229  directs sound in a direction that is parallel to and away from diaphragm  2208 . A third portion  2232  of U-shaped channel  2229  directs sound in a direction away from rear cover  2220  towards front cover  2217  and out of the sound port  2203 . 
     In some embodiments second portion  2231  of U-shaped channel  2229  is defined by frame  2207  and a channel cover  2233 . In some embodiments U-shaped channel  2229  enables sound port  2203  to be positioned away from diaphragm  2208 , acting as a sound channel that enables acoustic energy generated by driver assembly  2202  to be ported to a location remote from the driver assembly. In the embodiment illustrated in  FIG. 17C , U-shaped channel  2229  enables an aperture  2247  of sound port  2203  to be positioned substantially parallel to diaphragm  2208  and located a distance greater than 1 millimeter away from the perimeter of speaker opening  2209 . In other embodiments aperture  2247  of sound port  2203  can be positioned a distance at least 2 millimeters away and in other embodiments at least 4 millimeters away from the perimeter of speaker opening  2209 . In further embodiments aperture  2247  of sound port  2203  can be oriented differently and acoustic energy can be coupled to it from the driver assembly using a different shape of channel. 
     In some embodiments a panel of acoustic mesh  2234  is disposed within U-shaped channel  2229  and can have a perimeter attached to one or more walls  2235  that define the U-shaped channel. In various embodiments the perimeter of acoustic mesh  2234  can be insert-molded with one or more walls  2235  such that the acoustic mesh is an integral portion of frame  2207 . In some embodiments acoustic mesh  2234  can be oriented at an angle with respect to a plane of the diaphragm and/or a centerline of U-shaped channel  2229  to maximize a cross-sectional area of the acoustic mesh within the U-shaped channel. That is, instead of being oriented perpendicular to a longitudinal axis of U-shaped channel  2229 , acoustic mesh  2234  can be oriented at an angle to increase the area of the acoustic mesh within the U-shaped channel. Maximizing the cross-sectional area of acoustic mesh  2234  can enable less attenuation of the acoustic energy and less distortion of the sound as it passes through the acoustic mesh. 
     In some embodiments U-shaped channel  2229  and resonant cavity  2223  (see  FIG. 17B ) can be designed in conjunction with each other such that the U-shaped channel can result in attenuation of the frequency response in a particular frequency range and the resonant cavity can be designed to compensate for the attenuation such that audio module  2200  meets a desired frequency response requirement. More specifically, in some embodiments it may be desirable to for audio module  2200  to have equal loudness throughout the audible frequency range. U-shaped channel  2229  can act as a quarter wave resonant tube causing the sound waves in the tube to be 180 degrees out of phase with the sound waves of the driver assembly resulting in a reduction in loudness above the resonant frequency of the U-shaped channel. To compensate for the reduction in loudness, resonant cavity  2223  can be tuned to resonate at the same frequency as the quarter wave resonance of sound port  2203 . In some embodiments resonant cavity  2223  can extend the audible frequency bandwidth to increase loudness above and below the resonant frequency of the U-shaped channel. In various embodiments proper tuning of resonant cavity  2223  may utilize damping to widen the effective frequency range of the resonant cavity. Resonant cavity port  2225  can be used as such a damper to increase flow resistance to the air traveling in the narrow cross-sectional area of the port. 
       FIG. 17D  illustrates an isometric front view of frame  2207  that forms a portion of audio module  2200  illustrated in  FIG. 17A . As shown in  FIG. 17D , in some embodiments frame  2207  is an integrally formed structure that includes one or more electrical connections  2205 , one or more mounting tabs  2204 , acoustic mesh  2234 , top flux plate  2213  and one or more gaskets  2206  that are all formed as integral portions of frame. In some embodiments frame  2207  can be formed by performing a first insert molding operation that includes one or more electrical connections  2205 , one or more mounting tabs  2204 , acoustic mesh  2234  and top flux plate  2213 . A second insert molding operation can be performed on the resulting assembly to form one or more gaskets  2206  on sound port  2203  (see  FIG. 17A ). In some embodiments one or more gaskets  2206  can be formed using a low durometer rated material such as a rubber or silicone and can form not only an acoustic seal to the electronic device within which acoustic module  2200  is mounted, but can also form a water-tight seal to the electronic device. Frame  2207  can be made from a plastic material that is formulated to work with an insert-molding process. 
     Frame  2207  can also include a barometric vent  2236  that allows air into back volume  2222  (by way of the sound port  2203 , and out of the back volume to the sound port such that the back volume equilibrates with ambient air (e.g., air outside of the electronic device). In some embodiments barometric vent  2236  is covered with a porous material that enables back volume  2222  (see  FIG. 17B ) to equilibrate with ambient air but does not allow acoustic energy to pass between the back volume and front volume  2218 . 
     Frame  2207  can further include resonant cavity port  2225  that couples front volume  2218  (see  FIG. 17B ) with resonant cavity  2223 . In some embodiments resonant cavity  2223  can be used to adjust the frequency response of audio module  2200 , as described above. 
       FIG. 17E  illustrates an isometric back view of frame  2207  that forms a portion of audio module  2200  illustrated in  FIG. 17A . As shown in  FIG. 17E , in some embodiments frame  2207  includes a portion of resonant cavity  2223  that is coupled to front volume  2218  with resonant cavity port  2225 . A resonant cavity cover (not shown in  FIG. 17D ) can be attached to resonant cavity wall  2238 . A portion of an outer wall  2239  of frame  2207  defines a portion of back volume  2222  and a rear cover (not shown in  FIG. 17D ) can be attached to the outer wall of the frame to seal the back volume from the internal portion of electronic device in which audio module  2200  is mounted. 
     More specifically, back volume  2222  can be sealed from air within an electronic device (such as electronic device  100  in  FIG. 1 ) so that diaphragm  2208  is not influenced by air pressure changes within the electronic device. Front volume  2218  can similarly be sealed from air pressure within the electronic device such that the only opening between enclosure  2201  and the ambient environment is sound port  2203 . All other portions of enclosure  2201  can be sealed. Sealing enclosure  2201  can insure that diaphragm  2208  is not influenced by air fluctuations within the electronic device, for example when electronic device  100  (see  FIG. 1 ) includes a touch sensitive, and/or force sensitive display that is routinely depressed by a user causing air pressure fluctuations within the enclosure. 
     Channel cover  2233  (not shown in  FIG. 17D ) can be attached to frame  2207  along perimeter  2237  to form a portion of U-shaped channel  2229 . The various covers described herein can be made from a plastic or a metal material and attached to frame  2207  with any method including an adhesive, ultra-sonic welding, heat staking, soldering, brazing, or any other process. In some embodiments the covers can be attached and an additional sealing material can be applied over the attachment area using a material such as, for example an epoxy or sealant. 
       FIG. 17F  illustrates an isometric view of magnetic assembly  2211 . In some embodiments magnetic assembly  2211  includes one or more magnets  2212  that can include a center magnet  2240  and a pair of outer magnets  2241   a ,  2241   b  that are positioned between bottom flux plate  2214  and top flux plate  2213 . In some embodiments top flux plate  2213  includes a center portion  2242  and an outer portion (shown in  FIG. 17D ) that is formed as a portion of frame  2207 . In various embodiments, bottom flux plate  2214  can form a first portion of rear cover  2220  (see  FIG. 17B ) that is secured to frame  2207  to define a portion of back volume  2222 , as described in more detail below. Bottom flux plate  2214  can include a first lip  2244  that can be coupled with another portion of rear cover  2200  as discussed below. Top flux plate  2213  and bottom flux plate  2214  can be formed from any high permeability material such as, for example a low-carbon steel. One or more magnets  2212  can be made from any magnetic material including, but not limited to rare-earth materials such as neodymium. 
       FIG. 17G  illustrates an isometric view of a second portion  2245  of rear cover  2220  that forms a portion of enclosure  2201  of audio module  2200  illustrated in  FIG. 17A . As shown in  FIG. 17G  second portion  2245  of rear cover  2220  includes a second lip  2246  that is configured to interface with first lip  2244  of bottom flux plate  2214 . More specifically, bottom flux plate  2214  and second portion  2245  of rear cover  2220  can be secured together at first and second lips,  2244 ,  2246 , respectively, to form a unitary rear cover  2220  that can be secured to frame  2207  to form a sealed back volume  2222  (see  FIG. 17B ). 
       FIG. 18  illustrates an isometric view of an alternative embodiment of a magnet assembly  2300  that can be used in place of magnet assembly  2211  (see  FIG. 17F ). As shown in  FIG. 18 , magnet assembly  2300  uses a metal injection molded (MIM) formed bottom flux plate  2301 , a center magnet  2302  and a top flux plate  2303 . Bottom flux plate  2301  includes two raised outer sections  2304   a ,  2304   b . Center magnet  2302  is positioned between top flux plate  2303  and bottom flux plate  2301 . Other geometries and configurations of magnet assembly  2300  are within the scope of this disclosure. 
     Thermal Distribution Assembly 
       FIG. 19  illustrates an exploded view of the thermal distribution assembly  190 , in accordance with some described embodiments. The thermal distribution assembly  190  may include several layers of material that provide not only heat transfer properties, but also structural support. The enhanced heat transfer properties and structural support may be useful when the thermal distribution assembly  190  is used in an electronic device (not shown) having a substantially non-metal exterior, such as the electronic device  100  (shown in  FIG. 2 ). 
     As shown, the thermal distribution assembly  190  may include several layers of material. For example, the thermal distribution assembly  190  may include a first layer  1502  formed from a first type material, which may include a durable material, such as stainless steel. The thermal distribution assembly  190  may further include a second layer  1504  formed from a second type material, which may include a material having a relatively high thermal conductivity, such as copper or graphite. In this regard, the second layer  1504  may be designed to redistribute, redirect, or otherwise spread heat away from a heat-generating component (not shown) that is thermal coupled with the thermal distribution assembly  190 . For example, the thermal distribution assembly  190  may include a first layer  1502  formed from a third type material. However, the third type material may also include a durable material, such as stainless steel. 
     In order to assemble the thermal distribution assembly  190 , the various layers may undergo a cladding operation designed to bond the layers together of different material makeup. The cladding operation can include each layer of material on separate rollers, and then receiving each of the layers and pressing the layers together. The pressing effect may create molecular bonds between molecules of the metals. It should be noted that the cladding operation can be used when the second layer  1504  includes copper. A different assembly operation may be used when the second layer  1504  includes graphite. This will be illustrated below. Also, when assembled, the first layer  1502  and the third layer  1506  may provide a supporting structure for the second layer  1504 , and may also provide some structural support to an electronic device (not shown) that carries the thermal distribution assembly  190 . 
       FIG. 20  illustrates a side view of an embodiment of the electronic device  100 , showing the thermal distribution assembly  190  positioned in the electronic device  100 . As shown, the thermal distribution assembly  190  may be thermally coupled with the circuit assembly  170  such that heat generated from operational components of the circuit assembly  170  may be extracted from the circuit assembly  170  by the thermal distribution assembly  190 . Also, in some instances, the thermal distribution assembly  190  engages the band  110 . For example, the thermal distribution assembly  190  may engage the third part  116  and the fourth part  118 , both of which are metal sidewall features of the band  110 . In this regard, the thermal distribution assembly  190  may thermally couple with the band  110 , and the thermal distribution assembly  190  may provide a thermal bridge between the circuit assembly  170  and the band  110 . For example, as shown in the enlarged view, the second layer  1504  of the thermal distribution assembly  190  may receive heat (represented by dotted lines with arrow) generated from operational components of the circuit assembly  170 . The heat may pass through the second layer  1504  and to the band  110 , wherein the heat may dissipate to the ambient air. Furthermore, the thermal distribution assembly  190  may prevent or limit the second protective layer  144  from receiving thermal energy generated from operational components of the circuit assembly  170 . 
     Also, with the thermal distribution assembly  190  engaged with the band  110 , the thermal distribution assembly  190  may provide a rigid layer that supports the second protective layer  144 . For example, the first layer  1502  and the third layer  1506  of the thermal distribution assembly  190  may extend across a major surface of the second protective layer  144 . 
       FIG. 21  illustrates a side view of an alternative embodiment of a thermal distribution assembly  1600 , in accordance with some described embodiments. The thermal distribution assembly  1600  may include any material(s) and/or feature(s) previously described for a thermal distribution assembly. As shown, the thermal distribution assembly  1600  may include a first layer  1602 , a second layer  1604 , and a third layer  1606 , with the second layer  1604  embedded between the first layer  1602  and the third layer  1606 . Further, the second layer  1604  (shown as a dotted line) may be completely covered by the first layer  1602  and the third layer  1606 . This may prevent movement or shifting of the second layer  1604  relative to the first layer  1602  and/or the third layer  1606 . 
       FIG. 22  illustrates an isometric view of the thermal distribution assembly  1700  shown in  FIG. 21 , showing the thermal distribution assembly  1700  modified to receive a component  1710 . The thermal distribution assembly  1700  may include any material(s) and/or feature(s) previously described for a thermal distribution assembly. As shown, the thermal distribution assembly  1700  may include a first layer  1702 , a second layer  1704 , and a third layer  1706 , with the second layer  1704  embedded between the first layer  1702  and the third layer  1706 . 
     However, the second layer  1704  may be modified to reduce the dimensions of the thermal distribution assembly  1700 . For example, a portion of the second layer  1704  may be locally removed in a desired location such that the thermal distribution assembly  1700  includes only the first layer  1702  and the third layer  1706  define the thermal distribution assembly  1700 , thereby reducing (locally) the dimensions of the thermal distribution assembly  1700 . As a result of the reduced dimensions, the thermal distribution assembly  1700  defines a first channel  1712  that may receive the component  1710 . The reduced dimensions of the thermal distribution assembly  1700  further define a second channel  1714  that may receive a second component (not shown). 
     The component  1710  can be secured with the thermal distribution assembly  1700  by welding, soldering, or adhering (by adhesives), as non-limiting examples. Also, the dimensions of the first channel  1712  allow the component  1710  to be seated in the thermal distribution assembly  1700  such that the component  1710  is at least co-planar with respect to the first layer  1702 , or even sub-flush with respect to the first layer  1702 . It should be noted that the dimensions of the second channel  1714  may allow a second component (not shown) to be seated in the thermal distribution assembly  1700  such that the second component is at least co-planar with respect to the third layer  1706 , or even sub-flush with respect to the third layer  1706 . Also, the component  1710  may be representation of one or more components, such as a circuit assembly that includes one or more circuit boards, an audio module, a bracket, or a joint, as non-limiting examples. 
       FIG. 23  illustrates an isometric view of an alternative embodiment of a thermal distribution assembly  1800 , in accordance with some described embodiments. The thermal distribution assembly  1800  may include any material(s) and/or feature(s) previously described for a thermal distribution assembly. As shown, the thermal distribution assembly  1800  may include a first layer  1802 , a second layer  1804 , and a third layer  1806 , with the second layer  1804  between the first layer  1802  and the third layer  1806 . 
     In some embodiments, the second layer  1804  includes a metal, such as copper. In the embodiment shown in  FIG. 23 , the second layer  1804  includes graphite. In order to bond the second layer  1804  with the first layer  1802  and the third layer  1806 , the thermal distribution assembly  1800  may undergo a welding operation. For example, as shown in  FIG. 13 , the a thermal distribution assembly  1800  include several welds, such as a first weld  1812  and a second weld  1814  that are representative of several welds between the first layer  1802  and the second layer  1804 . However, the thermal distribution assembly  1800  may include several welds between the third layer  1806  and the second layer  1804 , as represented by the third weld  1816 . By welding the second layer  1804  with the first layer  1802  and the third layer  1806 , the second layer  1804  may resist shear forces that would otherwise displace the second layer with respect to the first layer  1802  and the third layer  1806 , particularly when the second layer  1804  includes a granular material, such as graphite. 
       FIG. 24  illustrates a flowchart  1900  showing a method for forming an electronic device, in accordance with some described embodiments. The electronic device may include a band formed from a metal defining a metal ring. Further, the band may be split into multiple sections, with the multiple sections electrically isolated from each other. Also, the band may be secured with a protective layer formed from a transparent material, such as glass, plastic, or sapphire. In this manner, the band may combine with the protective layer to form an internal cavity that receives several internal components. 
     In step  1902 , a display assembly is inserted into the internal cavity. The display assembly may include a touch sensitive layer, a display, and a force sensitive layer. The display may include an OLED display designed to flex or bend. Also, a protective layer formed from a transparent material may cover the display assembly. The protective layer may secure with a frame having a notch, or undercut, that partially receives the display as well as a flexible circuit that electrically and mechanically couples with the touch sensitive layer. However, in another location, the frame may not include the notch. In some embodiments, the force sensitive layer is electrically and mechanically coupled with a flexible that a location in which the frame does not include the notch. Accordingly, the touch sensitive layer and the force sensitive layer may electrically and mechanically couple with their respective flexible circuits in different locations of the electronic device. 
     In step  1904 , an internal power supply is inserted into the internal cavity. The internal power supply may include several electrodes formed by a die cutting process. In this manner, the internal power supply may take on a generally rectangular shape. The die cutting operation allows for a variety of shapes and sizes, and may maximize the volume of the internal power supply to improve the energy storage of the internal power supply. Also, the internal power supply may include channel designed to create space for components, such as a flexible circuit. In this manner, various internal components (such as antennae) may be rearranged in different locations and be in electrical communication with other components by way of the flexible circuit (or flexible circuits) passing along the channel. 
     In step  1906 , a circuit assembly is inserted into the internal cavity. The circuit assembly may include two (or more) circuit boards in a stacked configuration, in which a first circuit board is positioned over a second circuit board, as an example. The stacked configuration may create additional space in the internal cavity for other components, such as the internal power supply. The first circuit board may carry operational components (integrated circuits, transistors, etc.) on at least two opposing surfaces, with one of the surfaces facing a surface of the second circuit board. Further, the second circuit board may also carry several operational components on the surface facing the surface of the first circuit board. Also, operational components on the same surface may be in communication with each other by several metal traces, while operational components on opposing surfaces of a circuit board may be in communication with each other by a via (or by several vias). Also, operational components on different (stacked) circuit boards may be in communication with each other by several interposer boards designed to carry signals between the first circuit board and the second circuit board. Alternatively, or in combination, a flexible circuit may be electrically coupled with the first circuit board and the second circuit board by a hot bar soldering operation. 
     In step  1908 , an audio module is inserted into the internal cavity. The audio module may include a housing that carries several internal components, such as a diaphragm, a sound coil and a magnet, as non-limiting examples. The housing may include an opening aligned with an opening (or openings) of the band. Also, the diaphragm, as well as structural features that support the diaphragm, may separate the housing into a front volume and a back volume. The front volume may be in communication with the opening, while the back volume is sealed from air pressure in the internal cavity. In this manner, the diaphragm is not influenced by fluctuations in air pressure in the internal cavity. 
     In step  1910 , a thermal distribution assembly is inserted into the internal cavity. The thermal distribution assembly may include a first layer, a second layer, and a third layer, with the second layer positioned between the first layer and the second layer. The first layer may include a first type material, which can include metal such as stainless steel. The second layer may include a second type material, which can include copper or graphite. The third layer may include the first type material. The second layer is designed to provide a thermally conductive path for the electronic device, while the first layer and the third layer provide a protective cover for the second layer as well as structural support for the electronic device. Also, the thermal distribution assembly may limit or prevent the protective cover (that defines the internal cavity) from excessive heat to avoid injury to a user. 
     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: 20170908
Publication Date: 20190226
Grant Date: 20190226
Priority Date: 20160922
Inventors: LUCE, THOMAS R.
GRAZIAN, ANTHONY P.
TAO, HONGDAN
WILK, CHRISTOPHER
JARVIS, DANIEL W.
PAKULA, DAVID A.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04R2400/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R1/023", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2811", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/028", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/025", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R7/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2811", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2499/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R2400/11", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04R9/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R9/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R7/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/2811", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/028", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04R1/025", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04R1/023", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 61621488