Patent Publication Number: US-11653466-B2

Title: Components of an electronic device and methods for their assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/032,956, filed Sep. 25, 2020, entitled “COMPONENTS OF AN ELECTRONIC DEVICE AND METHODS FOR THEIR ASSEMBLY,” which is a continuation of U.S. patent application Ser. No. 16/404,498, filed May 6, 2019, entitled “COMPONENTS OF AN ELECTRONIC DEVICE AND METHODS FOR THEIR ASSEMBLY,” issued as U.S. Pat. No. 10,849,244 on Nov. 24, 2020, which is a continuation of U.S. patent application Ser. No. 16/042,992, filed Jul. 23, 2018, entitled “COMPONENTS OF AN ELECTRONIC DEVICE AND METHODS FOR THEIR ASSEMBLY,” issued as U.S. Pat. No. 10,285,295 on May 7, 2019, which is a continuation of U.S. patent application Ser. No. 15/832,606, filed Dec. 5, 2017, entitled “COMPONENTS OF AN ELECTRONIC DEVICE AND METHODS FOR THEIR ASSEMBLY,” issued as 10,034,402 on Jul. 24, 2018, which is continuation of U.S. patent application Ser. No. 14/821,620, filed Aug. 7, 2015, entitled “COMPONENTS OF AN ELECTRONIC DEVICE AND METHODS FOR THEIR ASSEMBLY,” issued as U.S. Pat. No. 9,854,694 on Dec. 26, 2017, which is a continuation of U.S. patent application Ser. No. 13/610,773, filed Sep. 11, 2012, entitled “COMPONENTS OF AN ELECTRONIC DEVICE AND METHODS FOR THEIR ASSEMBLY,” issued as U.S. Pat. No. 9,114,487 on Aug. 25, 2015, which claims the benefit of U.S. Provisional Patent Application No. 61/689,170, filed May 29, 2012, entitled “Component for an electronic device,” the contents of which are incorporated herein by reference in their entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     Various components of an electronic device housing and methods for their assembly are disclosed. 
     BACKGROUND 
     Portable electronic devices may be constructed using different approaches. For instance, an electronic device can be constructed by assembling several components together. These “components” can include external components that are combined to form a device enclosure (e.g., a device “housing”), as well as internal components that may provide structural support or other functionality for the electronic device (e.g., coupling members, fasteners, and electronic components). Based on the design of the electronic device, the external and internal components can be formed from any suitable material(s) including metals and plastics. 
     SUMMARY 
     Portable electronic devices are disclosed. A portable electronic device may be assembled from a number of internal and external components. In particular, the portable electronic device may include an enclosure assembled from two or more sections physically joined together with coupling members. A cover glass may be coupled to an outside edge of the disclosure, and the cover glass and enclosure, together, can define a volume for retaining the internal components of the electronic device. 
     According to some embodiments, the sections of the enclosure may be formed from one or more electrically conducting materials. The coupling members may be formed from one or more dielectric, insulating materials, which can electrically isolate the various electrically conductive sections of the enclosure. The coupling members may also span an entire width of the enclosure. Cover plates can be coupled to the coupling members on a side of the electronic device opposing the cover glass. 
     According to some embodiments, the sections of the enclosure may be formed from separately extruded parts. For example, the enclosure may include a top section, a center section, and a bottom section that are extruded separately and joined together using coupling members. The extruded sections of the enclosure may be assembled such that the longitudinal extrusion axes of one or more of the sections (e.g., the top and bottom sections) are perpendicular to the longitudinal axis of at least one other section (e.g., the center section). Materials and extrusion parameters may be chosen such that the separately extruded sections have a continuous, unibody appearance once they are joined together by the coupling members. In particular, grains in the extruded sections may be minimized or eliminated or appear continuous between the extruded sections of the enclosure. 
     According to further embodiments, the coupling members may be formed using a two-shot molding process in which the first shot physically couples together two or more of the sections of the enclosure. The sections may include locking members along their edges to facilitate the physical coupling during the first shot. The second shot can form one or more cosmetic structures that may be visible to a user of the electronic device. In some embodiments, the cosmetic structures may be exposed to one or more harsh manufacturing processes and/or chemicals. Accordingly, the cosmetic structures may include materials chosen for their ability to maintain an aesthetically pleasing appearance while withstanding such processing. 
     According to still further embodiments, one or more peripheral edges of the enclosure may be chamfered or otherwise trimmed for aesthetic and/or tactile purposes. The edge(s) may be trimmed, for example, after the first-shot molding process but before the second-shot molding process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic perspective view of a portable electronic device configured in accordance with an embodiment of the disclosure. 
         FIG.  2    is a schematic perspective view of a subassembly of a portable electronic device in accordance with some embodiments of the disclosure. 
         FIG.  3    shows a top view of an outer periphery component of an electronic device in accordance with some embodiments. 
         FIG.  4    shows a perspective view of the back side of an outer periphery component in accordance with some embodiments. 
         FIG.  5    shows a detailed cross-sectional view of an outer periphery component in accordance with some embodiments. 
         FIG.  6    shows an exploded view of the detailed view of the outer periphery component shown in  FIG.  5    in accordance with some embodiments. 
         FIG.  7    shows a perspective view of extruded sections of an electronic device housing in accordance with some embodiments. 
         FIG.  8    shows a perspective view of a portion of an outer periphery component of an electronic device including one or more retention holes formed therethrough in accordance with some embodiments. 
         FIGS.  9 A and  9 B  show a threaded insert positionable within retention hole  860 , which can include one or more elements for receiving a fastener in accordance with some embodiments. 
         FIG.  10    shows a perspective view of an outer periphery component including cover plates in accordance with some embodiments. 
         FIG.  11    shows a cross-sectional view of biasing mechanisms passed through holes in a coupling member towards the underside of a cover plate to bias cover plate against a flat datum surface in accordance with some embodiments. 
         FIGS.  12 - 15    show illustrative processes for creating a housing for an electronic device in accordance with some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following disclosure describes various embodiments of electronic devices, such as portable electronic devices including, for example, cellular telephones, and the like. Certain details are set forth in the following description and FIGS. to provide a thorough understanding of various embodiments of the present technology. Moreover, various features, structures, and/or characteristics of the present technology can be combined in other suitable structures and environments. In other instances, well-known structures, materials, operations, and/or systems are not shown or described in detail in the following disclosure to avoid unnecessarily obscuring the description of the various embodiments of the technology. Those of ordinary skill in the art will recognize, however, that the present technology can be practiced without one or more of the details set forth herein, or with other structures, methods, components, and so forth. 
     The accompanying FIGS. depict several features of embodiments of the present technology and are not intended to be limiting of its scope. Many of the details, dimensions, angles, and other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles, and/or features without departing from the spirit or scope of the present disclosure. 
     An electronic device can include several components assembled together to form internal and/or external features of the electronic device. For example, one or more internal components (e.g., electrical circuitry and/or internal support structures) can be placed within external components (e.g., housing structures) to provide an electronic device having desired functionality. As used herein, the term “component” refers to a distinct entity of an electronic device. Components may include, for example, electronic circuit elements (e.g., a microchip), one or more members forming the housing of the electronic device (e.g., a backplate or an outer periphery component), and internal support structures (e.g., a mid-plate). 
     In some cases, a component can be manufactured by assembling and connecting two or more different individual elements (i.e., “sections”) together. As used herein, the term “section” can refer to an individual portion of a component, where that component may be formed from multiple sections. The various sections of the component may then be coupled together using a “coupling member.” For example, the electronic device may include an enclosure component assembled from two or more sections, which are joined together with one or more coupling members. 
     Based on the desired functionality and design of the component and its sections, these coupling members can exhibit a wide range of shapes and structures. For example, the coupling members can include structural elements that can reinforce areas of high mechanical strain, counteract twisting movements at areas of high torsion, interlock two sections together such that they are mechanically coupled together, provide electrical isolation between two or more sections, and the like. 
       FIG.  1    is a schematic perspective view of an electronic device  10 . Electronic device  10  may be any one of a number of electronic devices including, but not limited to, cellular telephones, smartphones, other wireless communication devices, personal digital assistants, audio players, video players, game players, other media players, music recorders, video recorders, cameras, other media recorders, radios, medical devices, vehicle transportation instruments, calculators, programmable remote controls, pagers, laptop computers, desktop computers, printers, and combinations thereof. In some cases, electronic device  10  may perform multiple functions (e.g. play music, display video, store pictures, and receive and transmit telephone calls). 
     In the illustrated embodiment, electronic device  10  includes a body  11  incorporating a display  12 . Display  12  can include a cover or cover glass  14  that is operably coupled to a frame, housing, or enclosure  16 . In certain embodiments, display  12  may allow a user to interact with or control electronic device  10 . For example, display  12  and/or cover glass  14  can include touch-sensitive features to receive input commands from a user. In various embodiments, a cover or cover glass can encompass most of the surface area (e.g., 50%-100%) of one side of electronic device  10  (as shown in  FIG.  1   ), and a cover or cover plates can be positioned on an opposing side of electronic device  10  (not shown). As described in detail below, enclosure  16  and the cover glass  14  can at least partially house or enclose several internal components of the electronic device. According to some embodiments, cover glass  14  may be made from a glass (e.g., a pigmented or non-pigmented aluminosilicate glass) or other suitable material (e.g., sapphire). 
     In the embodiment illustrated in  FIG.  1   , enclosure  16  also at least partially defines several additional features of the electronic device  10 . In particular, the enclosure  16  can include audible speaker outlets  18 , a connector opening  20 , an audio jack opening  22 , a card opening  24  (e.g., SIM card opening), a front facing camera  26 . Though not shown in  FIG.  1   , enclosure  16  may also include a rear facing camera, a power button, and one or more volume buttons. Although  FIG.  1    schematically illustrates several of these features, one of ordinary skill in the art will appreciate that the relative size and location of these features can vary. 
     In certain embodiments, enclosure  16  can be made from a metallic material. For example, enclosure  16  can be made from aluminum or an aluminum alloy such as 6063 Aluminum. In other embodiments, however, enclosure  16  can be made from other materials, including suitable metals, alloys, and/or plastics. 
     As shown in  FIG.  1   , enclosure  16  can include opposing edge portions  30  (identified individually as a first edge portion  30   a  and a second edge portion  30   b ) extending around a periphery of the body  11 . In certain embodiments, one or both of edge portions  30  can have a chamfered, beveled, or other suitably shaped profile. As described in detail below, edge portions  30  may be formed to provide an aesthetically appealing appearance for enclosure  16 . 
     According to some embodiments, the exterior surface of enclosure  16  can be exposed to a first treatment, edge portions  30  may be formed, and the exterior surface of enclosure  16 , including edge portions  30 , can be exposed to a second treatment. In one embodiment, for example, a first anodization process can be applied to enclosure  16  before edge portions  30  are chamfered, and a second subsequent anodization process can be applied to enclosure  16  after edge portions  30  have been chamfered. Additional suitable surface treatments, including intermediary surface treatments, can be applied to enclosure  16  and/or edge portions  30 . In still further embodiments, edge portions  30  can have other suitable profiles or shapes including and/or surface treatments. 
     According to some embodiments, the anodization processes referred to above can be similar to those disclosed in co-pending U.S. Ser. No. 13/332,288, filed Dec. 20, 2011, entitled “METAL SURFACE AND PROCESS FOR TREATING A METAL SURFACE,” which is incorporated by reference herein in its entirety. In some embodiments, the anodization processes can be similar to those disclosed in U.S. patent application Ser. No. 13/610,813, filed Sep. 11, 2012, entitled, “DOUBLE ANODIZING PROCESSES,” the disclosure of which is incorporated by reference herein in its entirety. For example, the processes can include applying a mask to a portion of a metal surface (e.g., a portion of enclosure  16 ) using a photolithographic process. After the mask is applied, the metal surface can be exposed to one or more texturizing processes, including machining, brushing, blasting, or chemically etching the surface. 
     Further, the metal surface can be exposed to an anodization process, which can convert a portion of the metal surface into a metal oxide for increased corrosion resistance, wear resistance, and or to obtain a desired cosmetic effect (e.g., colorization via absorption of dyes or metals). The anodization process may be performed before or after the photolithographic mask is removed. In some embodiments, a first photolithographic mask can be removed and a second photolithographic mask can be applied before performing the anodization process. In still further embodiments, and as described above, the metal surface may be exposed to more than one anodization process. One or more finishing processes (e.g., polishing or sealing) may also be performed on the metal surface. In some embodiments, a first portion of the housing may be exposed to a first anodization process and a second portion of the housing may be exposed to a second anodization process. 
       FIG.  2    is a schematic perspective view of a subassembly  40  of electronic device  10  of  FIG.  1   . In the embodiment illustrated in  FIG.  2   , subassembly  40  includes enclosure  16  coupled to a cover glass, such as the cover glass  14  shown in  FIG.  1   . As shown in  FIG.  2   , enclosure  16  can include a first enclosure section  42  coupled to a second enclosure section  44 , which is in turn coupled to a third enclosure section  46 . Additionally, enclosure  16  can include a first coupling member  48  that couples first enclosure section  42  to second enclosure section  44  at a first interface  43 . Enclosure  16  can also include a second coupling member  50  that couples second enclosure section  44  to third enclosure section  46  at a second interface  45 . As assembled, subassembly  40  forms a five-sided structure, or tub, that can be enclosed on its sixth side by cover glass  14 . 
     In certain embodiments, the first, second, and third enclosure sections  42 ,  44 , and  46  can be metallic, and the first and second coupling members  48  and  50  can be made from one or more plastic materials. As described below in detail, for example, each of the first and second coupling members  48  and  50  can be formed from a two-shot molding process that may include a first plastic portion that joins the corresponding enclosure portions and a second cosmetic plastic portion that at least partially covers the first plastic portions. As further described in detail below, these plastic portions can be configured to withstand harsh chemicals and manufacturing processes (e.g., the texturizing and anodization processes described above) that may be used to form and process the enclosure. In further embodiments, the enclosure sections  42 ,  44 , and  46  and/or the first and second coupling members  48  and  50  can be made from any suitable materials including metallic, plastic, and/or other materials. 
     According to additional features of the embodiment illustrated in  FIG.  2   , enclosure  16  can include one or more low resistance conductive portions  52  (shown schematically) for grounding purposes. Conductive portion  52  can be formed by removing one or more layers or portions of the enclosure  16  to provide a lower resistance through enclosure  16  for antenna transmissions or communications. In certain embodiments, for example, the conductive portion  52  can be formed by laser etching or otherwise removing or etching an anodized portion of enclosure  16 . The exposed surfaces of conductive portion  52  can then be chemically treated to retain its electrical conductivity. Examples of suitable chemical treatment include chromate and non-chromate conversion coatings to passivate conductive portion  52 . These coatings can be applied using techniques including spraying and brushing using a paint brush. The conductivity of conductive portion  52 , as well as through different portions of enclosure  16 , can be tested using suitable techniques such as using resistance using probes at different points of conductive portion  52  and enclosure  16  to assure that ground can be established though enclosure  16 . 
     The illustrated subassembly  40  also includes several inserts  54  that can provide increased structural support and functionality for enclosure  16 . In embodiments in which the enclosure  16  is formed from aluminum, for example, inserts  54  can increase strength and durability of enclosure  16  by providing mounting points for structural and/or functional internal components. Additionally, in certain embodiments, inserts  54  can include threaded inserts or nuts that are configured to threadably engage a corresponding fastener. Inserts  54  formed from titanium may be advantageous as titanium can withstand harsh manufacturing processes and chemicals to which subassembly  40  may be subjected. In other embodiments, however, inserts  54  can be made from other suitable materials including, for example, steel, stainless steel, or brass. 
     According to yet additional features of the subassembly  40  not visible in  FIG.  2   , but described in detail below with respect to  FIGS.  10 ,  11 , and  15   , cover plates can be securely coupled, and offset if desired, relative to one side of the five-sided enclosure  16 . In particular, the cover plates can be aligned with a reference plane or datum relative to enclosure  16 . In order to maintain tight tolerance between the cover plates and enclosure sections  42 ,  44 , and  46 , enclosure  16  can include one or more access openings  56  that may be used to urge or bias the cover plates relative to the enclosure  16  for secure attachment (e.g., an adhesive attachment). For example, one or more springs may be inserted through access openings  56  to bias the cover plates against a planar structure until an applied adhesive sets. 
       FIG.  3    shows a top view of an outer periphery component  100  of an electronic device in accordance with some embodiments. In particular,  FIG.  3    shows a view of outer periphery component  100 , which may be assembled from sections  110 ,  120 , and  130 . Outer periphery component  100  may generally represent a more detailed view of subassembly  40  of  FIG.  2   . For example, top section  110 , center section  120 , and bottom section  130  may correspond to first enclosure section  42 , second enclosure section  44 , and third enclosure section  46 , respectively. Outer periphery component  100  can be constructed to form an exterior, peripheral surface for an electronic device. In particular, outer periphery component  100  can surround or enclose some or all of the internal components (e.g., electronic circuits, internal support structures, and the like) of the electronic device. In other words, outer periphery component  100  can define an internal volume into which internal components can be placed. 
     The thickness, length, height, and cross-section of outer periphery component  100  may be selected based on any suitable criteria including, for example, structural requirements (e.g., stiffness or resistance to bending, compression, and tension or torsion in particular orientations). In some embodiments, outer periphery component  100  can serve as a structural member to which other electronic device components can be mounted. Some of the structural integrity of outer periphery component  100  can come from the closed shape that it defines (e.g., outer periphery component  100  forms a loop, thus providing structural integrity). 
     Outer periphery component  100  can have any suitably shaped cross-section. For example, outer periphery component  100  can have a substantially rectangular cross-section. Each corner of the substantially rectangular cross-section can be chamfered or rounded in shape, thus forming a “spline.” As used herein, the term “spline” refers to a rounded corner portion of an outer periphery component. In some embodiments, outer periphery component  100  can have a cross-section in any other suitable shape including, for example, a circular shape, an oval shape, a polygonal shape, or a curved shape. In some embodiments, the shape or size of the cross-section of outer periphery component  100  can vary along the length or width of the electronic device (e.g., an hourglass shaped cross-section). The spline may be formed by trimming one or more edges of outer periphery component  100  as described in detail below with respect to  FIG.  4   . 
     Outer periphery component  100  of the electronic device can be constructed using any suitable process. In some embodiments, outer periphery component  100  can be constructed by connecting top section  110  and center section  120  together at interface  112 , and connecting center section  120  and bottom section  130  together at interface  122 . Although outer periphery component  100  is illustrated in  FIG.  3    as being constructed from three sections, one skilled in the art could appreciate that outer periphery component  100  could alternatively be formed from any suitable number of two or more sections, and that the interfaces between the sections may be positioned at any location on outer periphery component  100 . 
     Each section  110 ,  120 , and  130  can be constructed individually and later assembled to form outer periphery component  100 . For example, each section can be individually constructed using one or more of stamping, machining, working, casting, extrusion, or any combinations of these. In some embodiments, the materials selected for sections  110 ,  120 , and  130  can be conductive, thus allowing the sections to provide an electrical functionality for the electronic device. For example, sections  110 ,  120 , and  130  can be formed from a conductive material such as stainless steel or aluminum. In one particular embodiment, sections  110 ,  120 , and  130  may be constructed from 6063 Aluminum. In some embodiments, each section may serve as an antenna for the electronic device. 
     To mechanically couple individual sections together, coupling members  114  and  124  can exist at interfaces  112  and  122 , respectively. In some embodiments, each of the coupling members can be constructed from a material that can begin in a first state and may subsequently change to a second state. As an illustration, the coupling members can be constructed from a plastic that begins in a first, liquid state and then subsequently changes to a second, solid state. For example, the coupling members may be formed using one or more injection molding processes. 
     In some embodiments, the coupling member can be constructed from a glass-filled polyethylene terephthalate (“PET”). Alternatively, the coupling member can be constructed from a high-strength plastic such as polyaryletherketone (“PAEK”) or polyether ether ketone (“PEEK”). While in the liquid state, the plastic can be allowed to flow into interfaces  112  and  122 . After flowing into these interfaces, the plastic material may subsequently be allowed to harden into coupling members  114  and  124  (e.g., the plastic material is allowed to change into the second, solid state). Upon changing into the solid state, the plastic material may then physically bond top section  110  to center section  120  along a first edge of center section  120 , and center section  120  and bottom section  130  along a second edge of center section  120 , thus forming a single new component (e.g., outer periphery component  100 ). 
     Coupling members  114  and  124  not only physically couple together sections  110  and  120 , and sections  120  and  130 ; they may also electrically isolate top section  110  from center section  120 , and center section  120  from bottom section  130 . As will be explained in more detail below, coupling members  114  and  124  may include locking structures that are attached to integrally formed parts of sections  110 ,  120 , and  130 . That is, when the coupling member is in its first state (e.g., the liquid state), it can flow into and/or around the locking structures of section  110 ,  120 , and/or  130 . A shutoff device (e.g., an insert mold, not shown) may be positioned at each interface to shape the coupling member for when it transforms into its second state (e.g., the solid state). 
     Coupling members  114  and  124  can be constructed to span a width of outer periphery component  100 , as shown in  FIG.  3   . A portion of the coupling members  114  and  124  can interface with locking members existing on the sidewalls of sections  110 ,  120 , and  130 , and other portions of coupling members  114  and  124  can interface with additional locking members existing on the edge of the sections. In some embodiments, the physical coupling between coupling members  114  and  124  and sections  110 ,  120 , and  130  may be reinforced with one or more fasteners. 
       FIG.  4    shows a perspective view of the back side of outer periphery component  100  in accordance with some embodiments. Outer periphery component can include top section  110 , center section  120 , bottom section  130 , and interfaces  112  and  122 . As can be seen in  FIG.  4   , center section  120  can form three sides of the five-sided outer periphery component  100 , which can form a tub shape. The three sides of center section  120  can include a planar region  120   a , a first sidewall  120   s , and a second sidewall (not visible). The sidewalls may extend perpendicularly from planar region  120   a.    
     Top section  110  and bottom section  130  can each be U-shaped members that include outer surfaces  110   a  and  130   a , respectively. Top section  110  and bottom section  130  can also include inner surfaces (not shown). As assembled into outer periphery component  100 , a plane co-planar with planar region  120   a  of section  120  can be perpendicular to any plane that is co-planar with outer surfaces  110   a  and  130   a  of sections  110  and  130 . 
     Also visible in  FIG.  4    are cover plates  170   a  and  170   b , which will be discussed in more detail below with respect to  FIGS.  10  and  11   . Cover plates  170   a  and  170   b  may be coupled to outer periphery component  100  such that outer surfaces  171   a  and  171   b  are flush with an outer surface of at least one side of outer periphery component  100  (e.g., an outer surface of center section  120 ). Cover plates  170   a  and  170   b  may each encompass any suitable surface area on the side of outer periphery component  100  (e.g., 1% to 50%). 
     Outer periphery component  100  can also include chamfered edges  116   a  and  116   b . As noted above, chamfered edges can have any suitable shape (e.g., chamfer, round, or ogee), thus giving outer periphery component  100  any suitable cross-sectional shape. Chamfered edges  116   a  and  116   b  may be aesthetically and tactilely pleasing features for outer periphery component  100 . 
     According to some embodiments, chamfered edges  116   a  and  116   b  may be formed after one or more molding processes that are used to create one or more coupling members  114  and  124 . For example, top section  110  and center section  120  may be coupled together with coupling member  114  at interface  112 . Excess material from the molding of the coupling members that extends beyond the outer surface of outer periphery component  100  may be ground down, and outer periphery component  100  can be exposed to one or more finishing processes (e.g., anodization, texturization, or polishing). 
     One or more sections of the coupling members may then be machined to ready outer periphery component  100  for a second molding process, which can form cosmetic outward facing components for the coupling members. Excess material from the second molding process may be removed (e.g., ground down), and then chamfered edges  116   a  and  116   b  can be machined, trimmed, ground, or otherwise processed to produce a desired edge profile (e.g., a chamfered edge profile). For example, the excess material from the second molding process may be removed in a co-finishing process such that the material is flush with chamfered edges  116   a  and  116   b , planar region  120   a , first sidewall  120   s  (and the second sidewall, not visible), and outer surfaces  110   a  and  130   a  of sections  110  and  130 , respectively. After chamfered edges  116   a  and  116   b  are formed, outer periphery component  100  may be exposed to one or more additional finishing processes (e.g., a second anodization process). 
       FIG.  5    shows detailed cross-sectional view of a portion of outer periphery component  100  taken along line A-A′ of  FIG.  4   . In particular,  FIG.  5    shows a cross-sectional view of coupling member  114 , top section  110 , and a portion of center section  120  of outer periphery component  100 . Coupling member  114  (and coupling member  124 , which is not shown in this detailed view of outer periphery component  100 ) can be constructed to include a first-shot component  114   a  and a second-shot component  114   b.    
     Coupling members  114  and  124  (not shown) can be exposed to various physically and chemically harsh environments during the manufacturing process. For example, the side walls and back plate of an electronic device can undergo polishing or lapping operations, which can involve the use of very acidic (around pH 2) and/or very alkali (around pH 8-9) slurries depending on whether the polishing is a fine or rough polishing procedure. In addition, during a photolithography process, the device can be exposed to UV light during UV curing stage and developing stage, as well as exposure to a strong base such as sodium hydroxide for rinsing away non-cured photoresist material. Furthermore, during an anodizing process, the device can be subjected to a variety of acidic and alkali solutions at elevated temperatures and for extended amounts of time, as described above with reference to anodizing techniques. If a blasting, or other texturizing, procedure is used, the plastic material can be exposed to a pressurized blasting media. Additionally, during de-masking (used to remove photoresist material) the device can be exposed to acidic or alkali rinses solutions at elevated temperatures. Moreover, during a CNC the device can be exposed to cutting fluids. The first shot and second shot materials can be unaffected by one or more of the above described processes in that they can maintain structural integrity and can appear substantially unmarred. It should be noted that in some embodiments a mask can be used to prevent degradation of portions of plastic during some of the processes described above. For example, a mask can be used to protect plastic during higher intensity UV exposure during photolithography and during certain CNC steps to protect the plastic surface from scratching. Any suitable mask to protect the plastic can be used. In one embodiment, a UV curable polymer mask is used. 
     In embodiments described herein the materials used to form coupling members  114  and  124 , can be configured to withstand some or all the above described physical and chemical conditions. First-shot component  114   a  and second-shot component  114   b  can be made of different materials to serve different functions. In some embodiments, the first-shot component  114   a  can be formed from a relatively stronger material so as to provide structural support for the electronic device and second-shot component  114   b  can be formed from a softer but more cosmetically appealing material for aesthetic purposes. In certain embodiments, both first-shot component  114   a  and second-shot component  114   b  can be configured to withstand some or all of the above described physical and chemical conditions. For example, first-shot component  114   a  and second-shot component  114   b  can be formed from a high mechanical strength thermoplastic polymer resin such as a glass-filled PAEK or PEEK material. In other embodiments a glass-filled PET material can be used. In preferred embodiments, second-shot component  114   b  can appear smooth and even, thereby providing a more cosmetically appealing appearance than first-shot component  114   a . In some cases, the second-shot component  114   b  can take on any of a number of colors. 
     First-shot component  114   a  can be responsible for physically coupling together the sections (e.g., section  110  and section  120 ) of outer periphery component  100  and can be machined to include retaining regions for receiving the second shot. Second-shot component  114   b  can function as a cosmetic component that is self-anchored within the retaining region of first-shot component  114   a . Second-shot component  114   b  may be the only part of coupling member  114  that is visible to the user when the device is fully assembled. Because second-shot component  114   b  may be visible and exposed to the environment, including during one or more harsh processing steps, it can be formed from a material suitable for maintaining an aesthetically pleasing appearance (e.g., polyether imide (“PEI”)) notwithstanding such processing. Additionally, second-shot component  114   b  can have any suitable color. 
     According to some embodiments, first-shot component  114   a  can be injection molded between top section  110  and center section  120 . In particular, top section  110  and center section  120  can be inserted into an injection mold (not shown), and the material for forming first-shot component  114   a  can be injected into the mold cavity. In some embodiments, the injection mold may define one or more features and/or boundaries of first-shot component  114   a , including one or more of elements  161 - 167  and/or coupling member edge  115 . Alternatively, elements  161 - 167  and/or coupling member edge  115  can be formed (e.g., by grinding, machining, or otherwise trimming first-shot component  114   a ) after the material has cooled and set. 
     Coupling member  114  (and coupling member  124 , not shown) may be machined, for example, to have holes, recesses, retention features, or any other desired features after it is applied as a first shot. Such machined features are illustratively shown as elements  161 - 167 . For example, elements  161 - 164  are holes, and elements  165 - 167  are rectangular cutouts. These machine features may enable cables to pass from one side of the coupling member to another or to enable secure placement of various components such as a button, a camera, a microphone, a speaker, an audio jack, a receiver, a connector assembly, or the like. Additionally, one or more of elements  161 - 164  can be an antenna window via which an antenna can radiate and/or receive signals. 
       FIG.  6    shows an exploded view of the detailed view of coupling member  114 , top section  110 , and center section  120  of outer periphery component  100  shown in  FIG.  5   . First-shot component  114   a  can include interface features  141 - 147  for interfacing with locking mechanisms  151 - 159  of sections  110  and  120 . According to some embodiments, interface features  141 - 147  may be formed during a first-shot injection molding process in which the material that forms first-shot component  114   a  fills the interstices that define locking mechanisms  151 - 159  of sections  110  and  120 . 
     According to some embodiments, coupling member  114  can interface with sidewall locking mechanisms  151 - 154  and edge locking mechanisms  155 - 157  with sidewall interface features  141 - 144  and edge interface features  145 - 147 , respectively. In some embodiments, sidewall interface features  141 - 144  can be referred to as “knuckles.” In particular, sidewall interface features  141  and  143  can form a first knuckle, and sidewall interface features  142  and  144  can form a second knuckle. Edge interface features, on the other hand can be formed on a “span” of coupling member  114 , which extends between the two knuckles. When coupling member  114  is applied in a liquid state (e.g., into an injection mold), it can flow into and/or around locking mechanisms  151 - 157 . When the material sets and turns into a solid as coupling member  114 , it can form a physical interconnect that couples sections  110  and  120  together. Coupling member  114  can include fastener through-holes  148  and  149  that line up with holes and or inserts in section  110  such that screws or other fasteners can be used to secure coupling member  114  to section  110 . 
     First-shot component  114   a  may also include second-shot cavities  140  for receiving second-shot components  114   b . Second-shot cavities  140  may form recesses in first-shot component  114   a  at the interfaces between section  110  and section  120  (as well as section  120  and section  130 , not shown). According to some embodiments, second-shot cavities  140  may be formed after first-shot component  114   a  has been formed. In particular, portions of first-shot component  114   a  can be removed (e.g., by sawing, drilling, or machining) to form the recesses for second-shot cavities  140 . 
     Portions of sections  110  and  120  abutting first-shot component  114   a  may also be removed when forming second-shot cavities  140 . For example, second-shot cavities  140  can be created by sawing material away from first-shot component  114   a , section  110 , and section  120  at the interfaces between sections  110  and  120 . Accordingly, the width of second-shot cavities  140  can be repeated with accuracy, as the width is determined solely by the kerf of the saw. Accuracy and repeatability in the formation of second-shot cavities  140  may be advantageous for a number of reasons including, for example, antenna performance and aesthetic considerations. In some embodiments, a relatively small amount (e.g., 0.05-0.15 mm) of material may be removed from each of sections  110  and  120  during the formation of second-shot cavities  140 . 
     Both second-shot cavities  140  may be formed at the same time. In particular, in embodiments in which second-shot cavities  140  are formed by sawing first-shot component  114   a , and/or portions of sections  110  and  120 , second-shot cavities  140  can be cut together. Additionally, the same cut that forms second-shot cavities  140  can remove material from section  120  across the width of outer periphery component  100  between the second-shot cavities  140 . Accordingly, a straight, clean edge can be formed at the edge of section  120 , resulting in excellent alignment between the various components of outer periphery component  100 . 
     In further embodiments, second-shot cavities  140  may be formed as first-shot component  114   a  is molded (e.g., using features included in the injection mold). Second-shot components  114   b  may be purely cosmetic and configured to withstand harsh processing and/or chemicals while maintaining an attractive outward aesthetic. 
     In still further embodiments, coupling member  114  may include only first-shot component  114   a , with second-shot component  114   b  being formed integrally with first-shot component  114   a . That is, coupling member  114  may be formed from a one-shot molding process, and the material that forms first-shot component  114   a  may be visible from the outside of outer periphery component  100 . These embodiments may be preferable, for example, if the material used to form first-shot component  114   a  is aesthetically pleasing even after exposure to one or more harsh chemicals and/or processes. 
       FIG.  7    shows a perspective view of extruded sections  710 ,  720 , and  730  of an electronic device housing in accordance with some embodiments. Extruded sections  710 ,  720 , and  730  may be cut from extruded parts that are later machined to form sections  110 ,  120 , and  130 , as discussed above. In some embodiments, extruded sections  710 ,  720 , and  730  can be extruded separately in order to simplify the machining processes that will form sections  110 ,  120 , and  130 . Alternatively, two or more of extruded sections  710 ,  720 , and  730  may be cut from the same extruded part and cut to size (e.g., the relative sizes shown in  FIG.  7   ). For example, top extruded section  710  and bottom extruded section  730  may both be cut from the same extruded part. In some embodiments, one or more of extruded sections  710 ,  720 , or  730  may be bent during or after extrusion. 
     According to some embodiments, extruded sections  710 ,  720 , and  730  may be assembled such that the longitudinal extrusion axis (i.e., the axis along which the section was extruded) of at least one of the sections (e.g., top extruded section  710  and bottom extruded section  730 ) is perpendicular to the longitudinal extrusion axis of at least one other section (e.g., center extruded section  720 ). For example, the longitudinal extrusion axes of top extruded section  710  and bottom extruded section  730  may be parallel to the z-axis, while the longitudinal extrusion axis of center extruded section  720  may be parallel to the y-axis. One or more of extruded sections  710 ,  720 , and  730  may be oriented differently in order to facilitate machining of extruded sections  710 ,  720 , and  730  into, for example, sections  110 ,  120 , and  130 . For example, it may be difficult or impossible to form the five-sided tub structure of outer periphery component  100  of from a single extruded part or multiple extruded parts oriented along the same longitudinal extrusion axis. 
     One consequence of orienting one or more sections along different longitudinal extrusion axes is that visible grains, which are typical byproducts of extrusion processes, may not match between adjacent sections of the assembled electronic device. Accordingly, the materials and extrusion parameters used to form extruded sections  710 ,  720 , and  730 , as well as the final orientations of the sections, may be optimized to minimize the appearance of grain boundaries between adjacent sections. As just one example, extruded sections  710 ,  720 , and  730  may be formed from a material that is not susceptible to forming visual stretch marks during the extrusion process (e.g., 6063 Aluminum). Accordingly, extruded sections  710 ,  720 , and  730  may appear to have a smooth, continuous, unibody aesthetic after the extruded sections are machined and assembled. In particular, the five-sided outer periphery component  100 , which can be assembled from sections  110 ,  120 , and  130 , may appear to be one continuous, unibody component. 
     Assembling an electronic device housing from separate extruded sections (e.g., extruded sections  710 ,  720 , and  730 ) can be advantageous in several respects. For example, forming sections of an electronic device housing from extruded parts can be a cost effective and environmentally friendly alternative to conventional methods (e.g., die casting or molding) as the extrusion process can create long lengths of extruded parts that cut to appropriate lengths without excessive waste. Additionally, the availability of separately extruded sections can allow for the formation of detailed locking features (e.g., edge locking mechanisms  155 - 157  and sidewall locking mechanisms  151 - 154  of  FIG.  6    and retention holes  860  of  FIG.  8   ), which may not be possible if the housing is formed from a single molded part. 
       FIG.  8    shows a perspective view of a portion of outer periphery component  100  of an electronic device including one or more retention holes  860  formed therethrough in accordance with some embodiments. As shown in  FIG.  8   , one or more of section  120 , coupling member  114 , and section  110  may include one or more retention holes  860  formed therethrough (or partially therethrough). For example, retention holes  860  may be machined or otherwise formed through the material of center section  120  between a top surface  120   t  and a bottom surface  120   b  (not shown) of section  120 . Alternatively, retention holes  860  may extend only partially into the section  120  without reaching or extending through bottom surface  120   b.    
     In some embodiments, section  120  can be made from aluminum or an aluminum alloy (e.g., 6063 Aluminum), which may not be suitable for forming threads for receiving a screw. Therefore, the interior surface  860   i  of retention holes  860  may be substantially continuous and smooth, and thus may not be suitable for receiving and retaining a screw mechanism. A threaded insert  870  may be positioned within and retained by retention hole  860  such that a screw mechanism may be threadably retained within a portion of outer periphery component  100 . 
     As shown in  FIGS.  9 A and  9 B , a threaded insert  870  may be positioned within retention hole  860 . Threaded insert  870  can include one or more elements for receiving a fastener. For example, threaded insert  870  can include threads  872  for receiving and retaining a screw  880 . Threaded insert  870  may be made of any material (e.g., titanium) suitable for receiving and gripping screw  880  and withstanding harsh chemicals and/or processes (e.g., texturization and/or anodization). 
     Titanium may be particularly suitable for threaded insert  870 , because while titanium can anodize under the conditions used for anodizing aluminum, it will anodize only minimally and create little film growth. Thus, the titanium inserts will remain conductive and therefore suitable for electrical grounding, for example, even after undergoing an aluminum anodizing process. In addition, since anodization will occur minimally on titanium, the geometry of any threaded regions of the inserts may remain substantially the same. It should be noted that in addition to titanium, other suitable hard metals materials can be used for the threaded insert  870 , including magnesium, zinc, tantalum, or hard aluminum alloys such as 7075 Aluminum. Inserts made of softer aluminum alloys can be used, however the softer aluminum inserts may anodize in the aluminum anodizing bath. Therefore, in order to keep the aluminum inserts electrically conductive and to retain any threaded geometry, it can be necessary to mask the aluminum inserts using, for example polymer plugs, prior to exposure to the anodizing bath. However, this masking process can add time, cost, and manual labor to the process. 
     Threaded insert  870  may include a cap  874  that may be coupled to a body  875 . In some embodiments, cap  874  and body  875  can be integrally formed. The external surfaces of threaded insert  870  may be sized and shaped similarly to the size and shape of the internal surfaces of retention hole  860  such that threaded insert  870  can be positioned within retention hole  860 . For example, threaded insert  870  may be press fit into retention hole  860  (e.g., in the direction of arrow D). In some embodiments, an adhesive may be used to retain threaded insert  870  within retention hole  860 . 
     In some embodiments, at least a portion of cap  874  may have a larger cross-sectional area than a portion of body  875 . A top portion  862  of retention hole  860  may be larger than the remainder of retention hole  860 , such that top portion  862  may receive cap  874  and prevent cap  874  from being passed through the remainder of retention hole  860 . Moreover, cap  874  may include one or more protrusions  873  that may be received by one or more complimentary notches  863  in top portion  862  of retention hole  860 . When each protrusion  873  of cap  874  is aligned with and positioned within a respective notch  863  in top portion  862  of retention hole  860 , the interaction of each protrusion  873  and notch  863  may prevent threaded insert  870  from rotating with respect to retention hole  860  (e.g., in the direction of arrow S). 
     Threaded insert  870  may also include a threaded hollow  876  that may extend through at least a portion of cap  874  and/or through at least a portion of body  875 . The interior surface of threaded hollow  876  may include one or more threads  872  that may receive and retain complimentary threads  882  of a screw  880  that is rotated down into threaded hollow  876  (e.g., in the direction of arrow S). As mentioned, due to the interaction of each protrusion  873  and notch  863 , threaded insert  870  may be prevented from rotating within retention hole  860  in the direction of arrow S while screw  880  may be rotated within threaded hollow  876  of threaded insert  870  in the direction of arrow S. By positioning threaded insert  870  within retention hole  860  (e.g., of section  120 ) screw  880  may be screwed into and at least partially retained by threaded insert  870  within retention hole  860  such that screw  880  can couple section  120  (via threaded insert  870 ) to another component of the electronic device assembly (not shown). 
       FIG.  10    shows a perspective view of outer periphery component  100  including cover plates  170   a  and  170   b . After coupling members  114  and  124  have coupled top section  110  to center section  120  and center section  120  to bottom section  130 , respectively, cover plates  170   a  and  170   b  may be coupled to a bottom side of coupling members  114  and  124 , respectively. Cover plates  170   a  and  170   b  may be formed from any suitable material or combination of materials (e.g., pigmented glass, white ceramic glass, or sapphire) that may protect one or more components positioned within outer periphery component  100 . The material that forms cover plates  170   a  and  170   b  may be chosen for having a number of desirable qualities, including high strength, stiffness, and hardness or scratch resistance, transparency to radio frequencies, and/or opaqueness to visible light. The material also may be chosen based on aesthetic considerations (e.g., whether the color of the cover plate coordinates well with other colors of the electronic device incorporating outer periphery component  100  that are visible to a user). 
     According to some embodiments, cover plates  170   a  and  170   b  may be formed from a pigmented glass (e.g., pigmented aluminosilicate glass). The pigmented glass may be opaque to visible light in order to hide one or more internal components housed within outer periphery component  100  including, for example, coupling members  114  and  124 . In these embodiments, the pigmented glass can be treated with one or more processes to improve its hardness and stiffness. For example, the pigmented glass can be exposed to a potassium nitrate bath, which can initiate an ion exchange process that strengthens the glass. 
     Additionally, one or both sides of cover plates  170   a  and  170   b  (e.g., outer surfaces  171   a  and  171   b  and/or their respective opposing sides) formed from pigmented glass may be painted. Painting one or both sides of cover plates  170   a  and  170   b  with a dark paint can ensure that the cover plates are, indeed, opaque and add consistency between cover plates manufactured in different batches, lots, plants, etc. Cover plates  170   a  and  170   b  may be formed from pigmented glass in order to match dark colored features included elsewhere in outer periphery component  100  and/or the finished electronic device (e.g., electronic device  10  of  FIG.  1   ). 
     According to some further embodiments, cover plates  170   a  and  170   b  may be formed from a ceramic glass material. A base glass for forming the ceramic glass may be a glass (e.g., aluminosilicate glass) with several nucleation sites disposed throughout. The nucleation sites may be formed from any suitable impurity introduced into the base glass. The base glass can then be transformed into ceramic glass by exposure to one or more temperature cycling processes (e.g., raising and lowering the temperature of the base glass), which can promote crystal formation around the nucleation sites, thus forming the ceramic glass. In some embodiments, the ceramic glass may be an opaque, light colored (e.g., white, off white, or light gray) material. In these embodiments, the ceramic glass can be treated with one or more processes to improve its hardness and stiffness. For example, the ceramic glass can be exposed to a sodium nitrate bath, which can initiate an ion exchange process that strengthens the glass. 
     As with the pigmented glass, one or both sides of cover plates  170   a  and  170   b  formed from ceramic glass may be painted. Painting one or both sides of cover plates  170   a  and  170   b  with a light (e.g., white, off white, or gray) paint can ensure that the cover plates are opaque and add consistency between cover plates manufactured in different batches, lots, plants, etc. Cover plates  170   a  and  170   b  may be formed from ceramic glass in order to match light colored features included elsewhere in outer periphery component  100  and/or the finished electronic device (e.g., electronic device  10  of  FIG.  1   ). 
     According to still further embodiments, although they may be opaque to visible light frequencies (e.g., 390-750 THz), cover plates  170   a  and  170   b  may be transparent to light at frequencies (e.g., 500-6500 MHz) used for wireless communication. Accordingly, cover plates  170   a  and  170   b  may be used as antenna windows that allow antennas disposed proximate thereto to radiate and receive wireless signals. 
     According to some embodiments, cover plates  170   a  and  170   b  can be sliced to the appropriate thickness and cut to the appropriate lateral dimensions for incorporation into outer periphery component  100 . Cover plates  170   a  and  170   b  may also be exposed to one or more polishing steps (e.g., before and/or after the sodium or potassium nitrate strengthening baths). 
     Furthermore, it may be aesthetically and tactilely advantageous for outer surfaces  171   a  and  171   b  of cover plates  170   a  and  170   b  to be flush with outer surface  121  of section  120 . Accordingly, to ensure that outer periphery component  100  has a smooth and continuous outer surface, one or more springs or biasing mechanisms may be provided through coupling members  114  and  124  for supporting cover plates  170   a  and  170   b  with respect to coupling members  114  and  124  while an adhesive is allowed to set. The adhesive can adhere cover plates  170   a  and  170   b  to coupling members  114  and  124 , for example. 
     As shown in  FIG.  11   , one or more springs or biasing mechanisms  1104  (e.g.,  1104   a - c ) may be passed through holes  125  in coupling member  124  towards the underside of cover plate  170   b  to bias cover plate  170   b  against a flat datum surface  1100 . Outer surface  121  of section  120  may also be held against flat datum surface  1100 . According to some embodiments, each biasing mechanism may be independently controlled by its own biasing module  1102  (e.g.,  1102   a - c ) such that different portions of cover plate  170   b  may be biased with different biasing forces against flat datum surface  1100  for ensuring that all portions of outer surface  171   b  of cover plate  170   b  may be flush or in a continuous plane with outer surface  121  of section  120  while an adhesive (not shown) is allowed to dry. The adhesive may secure cover plate  170   b  to coupling member  124  and/or section  120  and/or section  130 . 
       FIG.  12    shows an illustrative process  1200  for creating a housing for an electronic device in accordance with some embodiments. Beginning at step  1201 , three separate sections of a housing can be formed. The three separate sections can include a top section, a center section, and a bottom section. According to some embodiments, the three separate sections may be extruded along a longitudinal extrusion axis and cut to the appropriate length (e.g., the lengths of extruded sections  710 ,  720 , and  730  of  FIG.  7   ). The three separate sections may be formed from a metallic material (e.g., aluminum, 6063 Aluminum, stainless steel, or any other suitable metal or alloy). One skilled in the art will appreciate that the housing for the electronic device may be assembled from any suitable number of sections (e.g., 2-5). 
     At step  1203 , each extruded section can be machined to include locking members and/or other suitable features. The locking members can be formed along one or more edges (e.g., edge locking mechanisms  155 - 157  of  FIG.  6   ) and/or sidewalls (e.g., sidewall locking mechanisms  151 - 154  of  FIG.  5   ) of each section. According to some embodiments, each extruded section may also be machined to reduce the thickness of the walls of the extruded sections. The walls of each extruded section may be machined to a thickness that will optimize the interior volume of the electronic device assembled from the sections while retaining suitable structural integrity. 
     At step  1205 , a first section is coupled to a second section with a first coupling member. Similarly, at step  1207 , the second section can be coupled to a third section with a second coupling member. For example, as shown in  FIG.  3   , top section  110  can be coupled to center section  120  with coupling member  114 , and center section  120  can be coupled to bottom section  130  with coupling member  124 . According to some embodiments, the coupling members can be formed at the same time (e.g., during a first-shot injection molding process). Accordingly, the three separate sections can be set within a mold, and the injection molding material (e.g., a suitable liquid plastic material such as PAEK or PEEK) can be injected into the mold. The injection molding material may be permitted to flow into one or more of the locking members of the sections and allowed to set, physically coupling the sections together. As an alternative, each of the coupling members can be formed separately. 
     At step  1209 , the first and second coupling members can be machined to form cosmetic cavities. Because the first and second coupling members may be responsible for adding structural support to the electronic device housing, the material that forms the coupling members may be chosen primarily for its strength. Accordingly, aesthetic considerations may be a secondary concern for the coupling members. However, as part of the coupling members may be visible on the exterior of the electronic device (e.g., at interfaces  112  and  122  of  FIG.  4   ), the portions of the coupling members that will be visible can be machined to create cosmetic cavities, (e.g., cavities suitable for receiving second-shot molded members). The second-shot material may be chosen primarily for its aesthetic qualities. 
     At step  1211 , cosmetic structures can be formed in the cosmetic cavities. According to some embodiments, the cosmetic structures may be formed in the cosmetic cavities using a second-shot injection molding process. As the cosmetic structures may be visible from the exterior of the electronic device, a suitable material (e.g., PEI) may be chosen for its ability to maintain a pleasing aesthetic appearance even after exposure to one or more harsh chemicals (e.g., sulfuric acid and nitric acid) and/or processes (e.g., UV light exposure and anodization). After the cosmetic structures are formed, one or more grinding or sanding processes may shape the cosmetic structures such that they are flush with the outer surfaces of the housing. 
     At step  1213 , first and second cover plates (e.g., cover plates  170   a  and  170   b  of  FIG.  10   ) can be fixed to the first and second coupling members, respectively. The first and second cover plates may be affixed to the first and second coupling members such that outer surfaces of the cover plates are co-planer with at least one outer surface of one of the sections (e.g., outer surface  121  of section  120 ). Alternatively, the cover plates may be offset by a desired distance from the datum surface defined by an outer surface of one of the sections. 
     According to some embodiments, one or more edges of the housing may be machined, trimmed, or otherwise altered to form an aesthetically and tactilely pleasing profile. For example, opposing edge portions  30  of  FIG.  1    can be machined to create chamfered edges. According to some embodiments, the edges can be machined after the cosmetic structures are formed at step  1211 . For instance, after the cosmetic structures are molded and shaped as described above, the edges of the housing (and portions of the cosmetic structures) can be machined to form a desired edge profile (e.g., a chamfered edge profile). After the edges are machined, the housing may be exposed to one or more finishing processes (e.g., anodization). Accordingly, both the material that forms the housing (e.g., 6063 Aluminum) and the material that forms the cosmetic structures (e.g., PEI) may be chosen to withstand, and maintain a pleasing external appearance, through the finishing processes. 
       FIG.  13    shows an illustrative process  1300  for creating a housing for an electronic device in accordance with some embodiments. Beginning at step  1301 , three separate sections of a housing can be formed. The three separate sections can include a top section, a center section, and a bottom section. According to some embodiments, the three separate sections may be extruded along a longitudinal extrusion axis and cut to the appropriate length (e.g., the lengths of extruded sections  710 ,  720 , and  730  of  FIG.  7   ). The three separate sections may be formed from a metallic material (e.g., aluminum, 6063 Aluminum, stainless steel, or any other suitable metal or alloy). One skilled in the art will appreciate that the housing for the electronic device may be assembled from any suitable number of sections (e.g., 2-5). 
     At step  1303 , at least one section can be machined to include retention holes (e.g., retention holes  860  of  FIG.  8   ). The retention holes may extend from a top surface of a section through a bottom surface (e.g., top surface  120   t  and bottom surface  120   b  of section  120  of  FIG.  9 A ). Alternatively, the retention holes may extend through the top surface of the section without reaching the bottom surface. 
     At step  1305 , a first section can coupled to a second section with a first coupling member. Similarly, at step  1307 , the second section can be coupled to a third section with a second coupling member. For example, steps  1305  and  1307  may substantially correspond to steps  1205  and  1207  as described above with respect to  FIG.  12   . 
     At step  1309 , the first and second coupling members can be machined to form holes corresponding to the retention holes of the at least one section. In particular, holes can be formed in the first and second coupling members at points where the coupling members overlap retention holes that were formed at step  1303 . In some embodiments, step  1303  may be omitted, and retention holes can be formed in at least on section and through the coupling members simultaneously (e.g., in step  1309 ). According to certain embodiments, a top section of the retention holes may be larger than the remainder of the retention holes. Furthermore, one or more notches may be formed in the top sections of the retention holes. 
     At step  1311 , threaded inserts (e.g., threaded insert  870  of  FIG.  9 A ) may be placed into the retention holes. The threaded inserts may have outer dimensions that correspond to the dimensions of the retention holes. For example, if the retention holes include top sections with wider cross-sectional areas than the remainder of the retention holes, the threaded inserts may have include a cap (e.g., cap  874  of  FIG.  9 A ) with a cross-sectional area corresponding to the top sections of the retention holes and a body (e.g., body  875  of  FIG.  9 A ) with a cross-sectional area corresponding to the remainder of the retention holes. According to some embodiments, the cap of the threaded insert can include one or more protrusions (e.g., protrusions  873  of  FIG.  9 A ) that correspond to notches in the top sections of the retention holes. 
     The threaded inserts may include a threaded hollow (e.g., threaded hollow  876 ) that may extend through at least a portion of the cap and/or through at least a portion of the body. The interior surface of the threaded hollow may include one or more threads (e.g., threads  872  of  FIG.  9 A ) that may receive and retain complimentary threads of a screw (e.g., threads  882  of screw  880  of  FIG.  9 B ) that can be rotated down into the threaded hollow. In some embodiments the threaded inserts may be formed from a metal (e.g., titanium). According to some embodiments, the threaded inserts may be press fit into the retention holes and/or affixed within the retention holes using an adhesive. 
     At step  1313 , fasteners (e.g., screws) may be retained within the threaded inserts. The fasteners may be used to mount or otherwise couple one or more internal components of the electronic device to the sections of the housing. For example, one or more circuit boards, structural reinforcing members, cameras, and/or other suitable internal components may be mounted within the electronic device housing assembled from the sections. 
       FIG.  14    shows an illustrative process  1400  for creating a housing for an electronic device in accordance with some embodiments. At step  1401 , at least one section of the housing can be extruded. According to some embodiments, a single member can be extruded along a longitudinal extrusion axis cut to lengths appropriate for the sections of the housing of the electronic device. For example, extruded sections  710 ,  720 , and  730  of  FIG.  7    may be cut from a single extruded member. In other embodiments, any of the sections of the housing can be extruded separately. For example, extruded sections  710 ,  720 , and  730  can each extruded separately and cut to length or extruded sections  710  and  730  may be cut from the same extruded member and center extruded section  720  may be extruded separately. 
     The sections may be formed from any suitable material (e.g., aluminum, 6063 Aluminum, stainless steel, or plastic). According to some embodiments, however, the material and various extrusion parameters (e.g., extrusion rate, temperature, etc.) may be chosen to minimize the appearance of any stretch marks or grains resulting from the extrusion process. For example, 6063 Aluminum may be chosen for the material. Accordingly, when the sections are joined together, the housing can appear to be of a seamless, unibody construction without noticeable grain boundaries between the sections. 
     At step  1403 , each extruded part can be machined to the desired dimensions of the housing. For example, the extruded parts can be machined to form sections  110 ,  120 , and  130  of  FIG.  3   . In particular, the thickness of the each extruded part can be machined to a thickness that can optimize the interior volume of the electronic device housing assembled from the sections while retaining suitable structural integrity. Other features may also be formed in the extruded parts at step  1403 , including one or more retention holes (e.g., retention holes  860  of  FIG.  8   ) and/or locking members (e.g., locking members  151 - 157  of  FIG.  6   ). 
     According to some embodiments, steps  1401  and  1403  may be combined. In particular, a single member can be extruded along a longitudinal extrusion axis and machined to form the desired dimensions of the housing. For example, a single member in the shape of a rectangular prism may be extruded and then material can be removed (e.g., by machining) to form the housing. The housing can be a five-walled, tub shaped housing with a rectangular, planar surface and four sidewalls extending perpendicularly from the rectangular, planar surface as depicted schematically in  FIG.  2   , for example. In some embodiments, the single member can be cut into individual sections (e.g., sections  710 ,  720 , and  730 ) before or after machining. Furthermore, additional material may be removed from one or more of the sections to form a window in the rectangular, planar surface. 
     At step  1405 , the sections can be rotated such that the longitudinal extrusion axis of at least one of the sections is oriented perpendicular to the longitudinal extrusion axis of at least one other section. For example, the longitudinal extrusion axes of two of the sections (e.g., top section  110  and bottom section  130 ) may be oriented perpendicular to the longitudinal extrusion axis of a third section (e.g., center section  120  of  FIG.  3   ). 
     At step  1407 , the sections can be physically coupled together using one or more coupling members to create the housing of the electronic device. This step may be substantially similar to those described in steps  1205  and  1207  of  FIG.  12   . 
       FIG.  15    shows an illustrative process  1500  for creating a housing for an electronic device in accordance with some embodiments. At step  1501 , cover plates can be coupled to coupling members accessible via a back side of an electronic device housing. For example, cover plates  170   a  and  170   b  can be coupled to coupling members  114  and  124 , respectively, of outer periphery component  100  of  FIG.  10   . According to some embodiments, the cover plates can be coupled to the electronic device housing with an adhesive (e.g., an epoxy). 
     At step  1503 , the electronic device housing can be placed against a planar datum surface. For example, to ensure that the outer surfaces of the cover plates are flush with an outer surface of the electronic device housing (e.g., outer surfaces of  171   a  and  17   b  of cover plates  170   a  and  170   b  are flush with outer surface  121  of section  120  of  FIG.  10   ), the outer surfaces can be placed against a planar datum surface (e.g., flat datum surface  1100  of  FIG.  11   ). The planar datum surface can be any flat surface external to the electronic device. 
     At step  1505 , the electronic device housing, including the cover plates, can be biased against the planar datum surface with one or more biasing mechanisms. For example, the electronic device can be biased against the planar datum surface with any suitable external force (e.g., a biasing mechanism such as a spring or gravity). Additionally, the cover plates can be biased against the planar datum surface with one or more biasing mechanisms (e.g., springs). The biasing mechanisms (e.g., biasing mechanisms  1104   a - c ) may be passed through holes (e.g., holes  125  in coupling member  124 ) towards the underside of the cover plates to the cover plates against the flat datum surface  1100 . According to some embodiments, each biasing mechanism can be separately controlled by a biasing module (e.g., biasing modules  1102   a - c ) such that different portions of the cover plates may be biased with different biasing forces against the flat datum surface to ensure that the outer surfaces of the cover plates and the outer surface of the electronic device are flush. At step  1507 , the adhesive may be allowed to dry while the electronic device housing is biased against the planar datum surface. 
     It should be understood that the processes described above are merely illustrative. Any of the steps may be removed, modified, or combined, and any additional steps may be added or steps may be performed in different orders, without departing from the scope of the invention. 
     The described embodiments of the invention are presented for the purpose of illustration and not of limitation.