PATENT DOCUMENT

Publication Number: US-12114453-B2
Application Number: US-201916449061-A
Country: US
Kind Code: B2

Title: Core shell with various filler materials for enhanced thermal conductivity

Abstract:
A composite housing of an electronic device can include a metal shell including a first material having a first set of material properties and a surface at least partially defining an exterior surface of the electronic device. The composite housing can also include an interior portion including a second material having a second set of material properties independent of the first set of material properties and at least partially defining a feature. The interior portion can be bonded to the shell and disposed interior to the surface of the shell.

Claims:
What is claimed is: 
     
       1. A housing of an electronic device, comprising:
 an elongate shell including a first metal having a first set of material properties and a surface having a substantially curved shape, the surface at least partially defining an exterior surface of the electronic device, the elongate_shell defining an engagement feature; and 
 an interior portion including a second metal having a second set of material properties independent of the first set of material properties and at least partially defining the engagement feature, the interior portion being bonded to the first metal of the elongate shell and disposed interior to the surface; 
 wherein the engagement feature defines a through hole having a central axis extending longitudinally along the elongate shell, the through hole defined and surrounded by the elongate shell and the interior portion. 
 
     
     
       2. The housing of  claim 1 , wherein:
 the elongate shell is pre-formed and has a thickness greater than about 25 microns; and 
 the interior portion and the elongate shell form a substantially unitary body. 
 
     
     
       3. The housing of  claim 1 , wherein the housing is positioned around a periphery of the electronic device and the surface at least partially defines a peripheral surface of the electronic device. 
     
     
       4. The housing of  claim 1 , wherein the interior portion is bonded to the elongate shell by welding, brazing, diffusion bonding, or mechanical engagement. 
     
     
       5. The housing of  claim 1 , further comprising an intermediate polymer layer disposed between the elongate shell and the interior portion, the intermediate polymer layer bonding the interior portion to the elongate shell. 
     
     
       6. The housing of  claim 1 , wherein the second metal is different than the first material. 
     
     
       7. A component for an electronic device, comprising:
 a first housing sidewall defining an exterior surface of the electronic device, the first housing sidewall comprising:
 a metal outer portion including a first material having a first set of material properties, the outer portion having a thickness greater than about 25 microns and at least partially defining the-exterior surface of the electronic device and an engagement feature; and 
 an inner portion bonded to the outer portion and including a second material having a second set of material properties independent of the first set of material properties, the inner portion defining an interior volume and at least partially defining the engagement feature, the engagement feature comprising an attachment feature for attaching to a part disposed in the interior volume, the attachment feature defining a through hole defined by the first material of the metal outer portion and the second material of the inner portion; and 
 
 a second housing sidewall defining the exterior surface, the second housing sidewall coupled to the first housing sidewall at the engagement feature; 
 wherein the inner portion and a pre-formed outer portion form a substantially unitary body. 
 
     
     
       8. The component of  claim 7 , wherein the first material comprises steel, aluminum, or titanium and the second material comprises copper, aluminum, or steel that is different than the first material. 
     
     
       9. The component of  claim 7 , wherein the inner portion is bonded to the pre-formed outer portion by welding, brazing, diffusion bonding, or mechanical engagement. 
     
     
       10. The component of  claim 7 , wherein the inner portion is bonded to the pre-formed outer portion by die casting the inner portion into the pre- formed outer portion. 
     
     
       11. The component of  claim 7 , further comprising an intermediate polymer layer disposed between and bonding the inner portion and the pre-formed outer portion. 
     
     
       12. The component of  claim 7 , wherein the inner portion comprises two layers bonded together and cooperating to define the feature. 
     
     
       13. The component of  claim 7 , wherein the feature is defined by both the inner portion and the pre-formed outer portion. 
     
     
       14. A method of forming a part for an electronic device, comprising:
 joining a pre-formed portion including a first material having a first material property to a second portion including a second material having a second material property independent of the first material property to form a unitary elongate body, the second portion defining an interior volume of the electronic device; and 
 forming one or more features in the second portion, the features defined by the pre-formed portion and the second portion and comprising an attachment feature configured to attach to a component disposed in the interior volume, the attachment feature defining a through hole axially aligned parallel with the elongate body, the through hole defined and surrounded by the first material and the second material. 
 
     
     
       15. The method of  claim 14 , wherein joining comprises welding or brazing the second portion to the pre-formed portion. 
     
     
       16. The method of  claim 14 , wherein joining comprises providing an intermediate layer between pre-formed portion and second portion. 
     
     
       17. The method of  claim 14 , wherein joining comprises die casting the second portion into the pre-formed portion. 
     
     
       18. A composite structure, comprising:
 a first shell material having a first set of material properties and defining a curved surface and a machined engagement feature defining a through hole, the curved surface at least partially defining an elongate exterior portion of an electronic device; and 
 a second core material having a second set of material properties independent of the first set of material properties and at least partially defining the machined engagement feature, the second core material disposed interior to the curved surface; 
 wherein: 
 the through hole is enclosed by the first shell material and the second core material; and 
 the through hole defines a central longitudinal axis generally parallel to the elongate exterior portion.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to U.S. Provisional Patent Application No. 62/798,343, filed 29 Jan. 2019, and entitled “CORE SHELL WITH VARIOUS FILLER MATERIALS FOR ENHANCED THERMAL CONDUCTIVITY,” the entire disclosure of which is hereby incorporated by reference. 
    
    
     FIELD 
     The described embodiments relate generally to electronic devices. More particularly, the present embodiments relate to enclosures for electronic devices. 
     BACKGROUND 
     Electronic devices are widespread in society and can take a variety of forms, from wristwatches to computers. Electronic devices, including portable electronic devices such as handheld phones, tablet computers, and watches, can experience contact with various surfaces during use. Further, use, transportation, and storage of such devices can exert mechanical and thermal stresses thereon. 
     Components for these devices, such as enclosures or housings, can benefit from exhibiting different combinations of properties relating to the use of the device. A housing for a portable electronic device can have a combination of properties, such as strength, appearance, toughness, abrasion resistance, weight, corrosion resistance, thermal conductivity, electromagnetic shielding, and cost, in order for the device to function as desired. Certain materials can provide a desired level of performance with respect to some properties, but may not provide an optimal level of performance with respect to others. Accordingly, it may be desirable to provide a device enclosure that can include multiple materials to achieve a desired level of performance with respect to as many properties as desired. 
     SUMMARY 
     According to some aspects of the present disclosure, a housing of an electronic device can include a metal shell including a first material having a first set of material properties and a surface having a substantially curved shape, the surface at least partially defining an exterior surface of the electronic device, and an interior portion including a second material having a second set of material properties independent of the first set of material properties and at least partially defining a feature, the interior portion being bonded to the shell and disposed interior to the surface. 
     In some cases, the metal shell is pre-formed and has a thickness greater than about 25 microns. The interior portion and the shell can form a substantially unitary body. The housing can be positioned around a periphery of the electronic device and the surface can at least partially define a peripheral surface of the electronic device. The interior portion can at least partially define an interior volume of the electronic device. The interior portion can be bonded to the pre-formed shell by welding, brazing, diffusion bonding, or mechanical engagement. The housing can include an intermediate polymer layer disposed between the pre-formed shell and the interior portion, the intermediate polymer layer bonding the interior portion to the pre-formed shell. The first material can include a first metal and the second material comprises a second metal or an alloy different than the first material. 
     According to some aspects, a component for an electronic device can include metal outer portion having a thickness greater than about 25 microns and including a first material having a first set of material properties, the outer portion at least partially defining an exterior surface of the electronic device, and an inner portion bonded to the outer portion and including a second material having a second set of material properties independent of the first set of material properties, the inner portion defining a feature and at least partially defining an interior volume of the electronic device, wherein the inner portion and the pre-formed outer portion form a substantially unitary body. 
     In some cases, the first material can include a first metal and the second material comprises a second metal. The first material can include a steel or aluminum alloy and the second material comprises a copper, aluminum, or steel alloy different than the first material. The first material can include titanium and the second material comprises copper, aluminum, or steel. The inner portion can be bonded to the pre-formed outer portion by welding, brazing, diffusion bonding, or mechanical engagement. The inner portion can be bonded to the pre-formed outer portion by die casting the inner portion into the pre-formed outer portion. The component can further include an intermediate polymer layer disposed between and bonding the inner portion and the pre-formed outer portion. The intermediate polymer layer can include a heat activated film or an injection molded polymer. The inner portion can include two layers bonded together and cooperating to define the feature. The feature can be defined by both the inner portion and the pre-formed outer portion. The pre-formed outer portion can have a thickness greater than about 25 microns. 
     According to some aspects, a method of forming a component for an electronic device can include joining a pre-formed portion including a first material having a first material property to a second portion including a second material having a second material property independent of the first material property to form a unitary body, and forming one or more features in the second portion. 
     In some cases, joining can include welding or brazing the second portion to the pre-formed portion. Joining can include providing an intermediate layer between pre-formed portion and second portion. Joining can include die casting the second portion into the pre-formed portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG.  1    shows a perspective view of an electronic device. 
         FIG.  2    shows an exploded view of an electronic device. 
         FIG.  3    shows an exploded view of a housing of an electronic device. 
         FIG.  4 A  shows an exploded perspective view of a component of an electronic device. 
         FIG.  4 B  shows a perspective view of a component of an electronic device. 
         FIG.  5    shows a perspective view of a portion of a housing of an electronic device. 
         FIG.  6    shows another perspective view of the portion of the housing of  FIG.  5   . 
         FIG.  7    shows a top view of the portion of the housing of  FIG.  5   . 
         FIG.  8    shows a side view of the portion of the housing of  FIG.  5   . 
         FIG.  9 A  shows a perspective view of a component of an electronic device. 
         FIG.  9 B  shows a perspective view of a component of an electronic device. 
         FIG.  10    shows a close-up perspective view of a portion of a housing of an electronic device. 
         FIG.  11    shows a close-up perspective view of a portion of a housing of an electronic device. 
         FIG.  12 A  shows an exploded perspective view of a component of an electronic device. 
         FIG.  12 B  shows a perspective view of a component of an electronic device. 
         FIG.  13    shows a perspective view of a portion of a housing of an electronic device. 
         FIG.  14    shows an exploded view of the portion of the housing of  FIG.  13   . 
         FIG.  15    shows a process flow diagram of a method for forming a component of an electronic device. 
         FIG.  16    shows a perspective view of a unitary body including a first material and a second material. 
         FIG.  17    shows a perspective view of a unitary body including a first material and a second material. 
         FIG.  18    shows a schematic diagram of stages of a method for forming a component of an electronic device. 
     
    
    
     DETAILED DESCRIPTION 
     The present description provides examples, and is not limiting of the scope, applicability, or configuration set forth in the claims. Thus, it will be understood that changes can be made in the function and arrangement of elements discussed without departing from the spirit and scope of the disclosure, and various embodiments can omit, substitute, or add other procedures or components as appropriate. For instance, methods described can be performed in an order different from that described, and various steps can be added, omitted, or combined. Also, features described with respect to some embodiments can be combined in other embodiments. 
     One aspect of the present disclosure relates to composite components for electronic devices, such as frames, housings, bands, or portions thereof for an electronic device. In some examples, a composite housing for an electronic device can include a pre-formed exterior or outer portion, also referred to as a shell, having a first set of material properties. The pre-formed exterior portion can include a metallic material, such as stainless steel. The composite housing can also include an interior or inner portion, also referred to as a core, having a second, different set of material properties that are independent of the first set of material properties. For example, the interior portion can include a metallic material such as aluminum. The pre-formed exterior portion and the interior portion can be welded, bonded, adhered, or otherwise joined together such that they form the housing, or a portion thereof, and act as a substantially unitary body. That is, in some cases, the composite component can be treated as a single piece or body of material with respect to various processes, such as the manufacturing and assembly processes described herein. 
     In some examples, a composite construction can allow for the decoupling of the material properties of the interior, primarily structural or functional portion of the housing, from the exterior, primarily cosmetic portion of the housing. That is, the material of the inner portion can be selected to exhibit one or more properties of the composite housing while the material of the exterior portion can be independently selected to exhibit one or more other desired properties of the housing. For example, in some cases, the material and/or geometry of the inner portion can be selected to achieve a desired level of strength, weight, stiffness, cost, thermal conductivity, electromagnetic transparency, machinability, carbon footprint, recyclability, other properties, or combinations thereof. Meanwhile, the material and/or geometry of the exterior portion can be independently selected in order to achieve a desired level of hardness, corrosion resistance, scratch resistance, cosmetic finish, strength, weight, stiffness, cost, thermal conductivity, electromagnetic transparency, machinability, carbon footprint, recyclability, other properties, or combinations thereof. 
     For example, a housing made primarily of a material such as stainless steel can provide a desired exterior cosmetic appearance and a desired level of stiffness, but can be relatively heavy and expensive, and features, such as attachment features, can be relatively difficult to machine and can result in high levels of material waste. On the other hand, a housing made primarily of aluminum can be lightweight, low cost, and easily machined, but may not provide a desired cosmetic appearance or scratch resistance. In contrast, a composite housing, as described herein and having an exterior portion including stainless steel joined to an interior portion including aluminum, can be lightweight, low cost, and easily machined relative to an entirely steel housing, but can have the desired cosmetic appearance, hardness, and scratch resistance of stainless steel. 
     In some examples, the interior or inner portion of the composite housing or component can include any material that has a desired material property or properties and can be welded, bonded, adhered, or otherwise joined to an exterior portion, as described herein. For example, the interior portion of the composite housing can include organic materials such as polymeric materials, ceramic materials, metallic materials, or combinations thereof. In some examples, the interior portion of a composite housing or component, as described herein, can include a metallic material such as aluminum, copper, steel, or alloys, or combinations thereof. In some examples, the interior portion can include a metallic material having a foamed structure or a bulk metallic glass. In some cases, the interior portion can be a composite material, such as a carbon reinforced polymer material, ceramic reinforced polymer material, a metal matrix composite material, a ceramic matrix composite material, or other composite materials. 
     In some examples, the interior portion of the composite housing or component can be primarily, substantially entirely, or at least partially responsible for the mechanical or structural properties of the composite housing or component. That is, the properties, such as weight, stiffness, thermal conductivity, etc. of the composite housing or component can be substantially similar to the properties of the material forming the interior portion. In some examples, the interior portion of the composite housing or component can have any desired thickness. For example, as described herein, the interior portion of the composite housing can have a thickness of several millimeters and can form a frame or a band around a portion of the periphery of an electronic device. In some examples, however, the interior portion of the composite housing can have a thickness such that it extends substantially entirely across an entire width of the electronic device. 
     In some examples, the exterior or outer portion of the composite housing or component can include any material that has a desired material property or properties and can be welded, bonded, adhered, or otherwise joined to an interior portion, as described herein. For example, the exterior portion can include organic materials such as polymeric materials, ceramic materials, metallic materials, or combinations thereof. In some examples, the exterior portion of a composite housing or component, as described herein, can include a metallic material such as steel, titanium, aluminum, or alloys, or combinations thereof. In other examples, the exterior portion can include precious or semi-precious metals such as silver, gold, platinum, or alloys, or combinations thereof. In yet additional examples, the exterior portion can include ceramic materials, such as alumina or sapphire, zirconia, carbides, nitrides, borides, oxides, or combinations thereof. In some examples, the exterior portion can include a metallic material such as a bulk metallic glass. In other examples, the exterior portion can itself be a composite material, such as a carbon reinforced polymer material, ceramic reinforced polymer material, a metal matrix composite material, a ceramic matrix composite material, or other composite materials. 
     In some examples, the exterior portion of the composite housing or component can be a pre-formed or standalone article prior to being joined to the inner portion to form the composite housing or component. That is, the material of the exterior portion can be a substantially unitary body, such as a blank, bar, strip, or piece of material. In some examples, however, the exterior portion can be formed from multiple bodies of material that are joined to the interior portion to form the composite housing or component. For example, two or more strips or sections of material can be joined to an interior portion to act as an exterior portion, and thereby form the composite housing or component. In some examples, the exterior portion is not a coating. That is, in some examples, the exterior portion is not grown, deposited, coated, or otherwise formed on the interior portion. 
     The exterior portion of the composite housing or component can have a thickness of greater than about 25 microns, greater than about 50 microns, greater than about 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, or more. In some examples, the exterior portion can have a thickness of up to about 1 millimeter, up to about 2 millimeters, or up to about 5 millimeters or more. Further, the exterior portion can have a thickness that varies along one or more positions of the exterior portion. For example, a feature can be formed in the exterior portion and the thickness adjacent to the feature can be about 1 millimeter or more, while some other areas of the exterior portion, where no feature is present, can have a thickness of about 100 microns. The desired thickness of the exterior portion can be dependent on the material of the exterior portion, the material of the interior portion, the desired properties of the final formed composite component, and combinations thereof. 
     The exterior portion and interior portion of the composite housing or component can be joined by any methods now known in the art or that may be developed in the future. In some examples, the exterior portion can be joined directed to the interior portion, such that a surface of the exterior portion directly contacts, abuts, is fused to, is bonded to, or is otherwise directly joined to the interior portion. In some examples, the exterior portion can be joined to the interior portion by welding, for example ultrasonic welding or laser welding, brazing, diffusion bonding, fusing, or other similar methods. In some examples, the exterior portion can form a metallurgical bond with the interior portion along at least a portion of the interface between the exterior and interior portions. 
     In some examples, the exterior and interior portions can be joined together with the use of an adhesive or another intermediate material. For example, the exterior and interior portions can be joined or secured together by a glue or an adhesive, such as a resin or an epoxy, by a heat activated film, by an injection molded plastic, or by similar joining methods. The exterior and interior portions can be alternatively or additionally joined or secured together via mechanical engagement between the portions. For example, features of the exterior portion can mechanically engage with features of the interior portion to mechanically join the portions together. These engagement features can range in size from nano- or micro-scaled features to macro-scale features having dimensions on the order of millimeters, and can include various combinations thereof. 
     In some examples, the interior portion can be formed into or onto the exterior portion such that a mechanical, metallurgical, other type of bond, or combinations thereof joins the exterior and interior portions. For example, the interior portion can be cast, molded, such as by metal injection molding, or otherwise formed into the pre-formed exterior portion. In this way, the material of the interior portion can flow into features on the surface of the exterior portion such that when the material of the interior portion solidifies, for example by cooling or curing, a mechanical, metallurgical, or other type of bond is formed between the interior and exterior portions. 
     Either or both of the interior and exterior portions of the composite component, such as a portion of a housing of an electronic device, can be subjected to treatment processes prior to, during, or subsequent to the joining process. For example, a surface of the exterior portion of the composite component can be subjected to a surface treatment, such as a physical vapor deposition process, after the composite component has been formed. A surface of the composite component including both the interior and exterior portion can be treated, for example, by an etching process or processes, to create one or more engagement features to facilitate joining the composite component to one or more other components of the electronic device. 
     These and other embodiments are discussed below with reference to  FIGS.  1 - 16   . The detailed description given herein with respect to these figures, however, is for explanatory purposes only and should not be construed as limiting. 
       FIG.  1    illustrates a perspective view of an embodiment of an electronic device  100 . The electronic device  100  shown in  FIG.  1    is a mobile wireless communication device, such as a smartphone. The smartphone of  FIG.  1    is merely one representative example of a device that can be used in conjunction with the systems and methods disclosed herein. Electronic device  100  can correspond to any form of wearable electronic device, a portable media player, a media storage device, a portable digital assistant (“PDA”), a tablet computer, a computer, a mobile communication device, a GPS unit, a remote control device, or other electronic device. The electronic device  100  can be referred to as an electronic device, or a consumer device. 
     The electronic device  100  can have a housing that includes a band or a frame  102  that defines an outer perimeter of the electronic device  100 . The band  102 , or portions thereof, can be or include a composite component, as described herein. In some examples, the band  102  can include several sidewall components, such as a first sidewall component  104 , a second sidewall component  106 , a third sidewall component  108  (opposite the first sidewall component  104 ), and a fourth sidewall component (not shown in  FIG.  1   ). The aforementioned sidewall components can be or include a composite component, as described herein. 
     In some instances, some of the sidewall components form part of an antenna assembly (not shown in  FIG.  1   ). As a result, a non-metal material or materials can separate the sidewall components of the band  102  from each other in order to electrically isolate the sidewall components. For example, a first separating material  112  separates the first sidewall component  104  from the second sidewall component  106 , and a second separating material  114  separates the second sidewall component  106  from the third sidewall component  108 . The aforementioned materials can include an electrically inert or insulating material(s), such as plastics and/or resin, as non-limiting examples. 
     The electronic device  100  can further include a display assembly  116  (shown as a dotted line) that is covered by a protective cover  118 . The display assembly  116  can include multiple layers (discussed below), with each layer providing a unique function. The display assembly  116  can be partially covered by a border  120  or a frame that extends along an outer edge of the protective cover  118  and partially covers an outer edge of the display assembly  116 . The border  120  can be positioned to hide or obscure any electrical and/or mechanical connections between the layers of the display assembly  116  and flexible circuit connectors. Also, the border  120  can include a uniform thickness. For example, the border  120  can include a thickness that generally does not change in the X- and Y-dimensions. 
     Also, as shown in  FIG.  1   , the display assembly  116  can include a notch  122 , representing an absence of the display assembly  116 . The notch  122  can allow for a vision system (discussed below) that provides the electronic device  100  with information for object recognition, such as facial recognition. In this regard, the electronic device  100  can include a masking layer with openings (shown as dotted lines) designed to hide or obscure the vision system, while the openings allow the vision system to provide the object recognition information. This will be further discussed below. Also, the protective cover  118  can be formed from a transparent material, such as glass, plastic, sapphire, or the like. In this regard, the protective cover  118  can be referred to as a transparent cover, a transparent protective cover, or a cover glass (when the protective cover  118  includes glass). As shown in  FIG.  1   , the protective cover  118  includes an opening  124 , which can represent a single opening of the protective cover  118 . The opening  124  can allow for transmission of acoustical energy (in the form of audible sound) into the electronic device  100 , which can be received by a microphone (not shown in  FIG.  1   ) of the electronic device  100 . The opening  124  can also, or alternatively, allow for transmission of acoustical energy (in the form of audible sound) out of the electronic device  100 , which can be generated by an audio module (not shown in  FIG.  1   ) of the electronic device  100 . Also, the electronic device  100  may not, in some embodiments, include a button, such as “home button,” commonly found in electronic devices, as the protective cover  118  may not include additional openings. 
     The electronic device  100  can further include a port  126  designed to receive a connector of a cable assembly. The port  126  allows the electronic device  100  to communicate data (send and receive), and also allows the electronic device  100  to receive electrical energy to charge a battery assembly. Accordingly, the port  126  can include terminals that electrically couple to the connector. 
     Also, the electronic device  100  can include several additional openings. For example, the electronic device  100  can include openings  128  that allow an additional audio module (not shown in  FIG.  1   ) of the electronic device to emit acoustical energy out of the electronic device  100 . The electronic device  100  can further include openings  132  that allow an additional microphone of the electronic device to receive acoustical energy. Furthermore, the electronic device  100  can include a first fastener  134  and a second fastener  136  designed to securely engage with a rail that is coupled to the protective cover  118 . In this regard, the first fastener  134  and the second fastener  136  are designed to couple the protective cover  118  with the band  102 . 
     The electronic device  100  can include several control inputs designed to facilitate transmission of a command to the electronic device  100 . For example, the electronic device  100  can include a first control input  142  and a second control input  144 . The aforementioned control inputs can be used to adjust the visual information presented on the display assembly  116  or the volume of acoustical energy output by an audio module, as non-limiting examples. The controls can include one of a switch or a button designed to generate a command or signal that is received by a processor. The control inputs can at least partially extend through openings in the sidewall components. For example, the second sidewall component  106  can include an opening  146  that receives the first control input  142 . Further details regarding the features and structure of an electronic device are provided below, with reference to  FIG.  2   . 
       FIG.  2    illustrates an exploded view of an electronic device  200 . The electronic device  200  shown in  FIG.  2    is a smartphone, but is merely one representative example of a device that can include or be used with the systems and methods described herein. As described with respect to electronic device  100 , electronic device  200  can correspond to any form of wearable electronic device, a portable media player, a media storage device, a portable digital assistant (“PDA”), a tablet computer, a computer, a mobile communication device, a GPS unit, a remote control device, and other similar electronic devices. In some cases, the electronic device  200  can include some or all of the features described herein with respect to electronic device  100 . 
     The electronic device can have a housing that includes a band  202  that at least partially defines an exterior portion, such as an outer perimeter, of the electronic device. As with the band  102  described above in  FIG.  1   , the band  202  can include several sidewall components, such as a first sidewall component  204 , a second sidewall component  206 , a third sidewall component  208  (opposite the first sidewall component  204 ), and a fourth sidewall component  210 . The aforementioned sidewall components can be or can include a composite component, as described herein. The band  202  can also include a non-metal material or materials that separate and/or join the sidewall components of the band  202  with each other, as described herein. For example, separating material  214  can separate and/or join the second sidewall component  206  with the third sidewall component  208 . 
     The housing, including the band  202 , can include one or more features to receive or couple to other components of the device  200 , such as feature  222 . For example, the band  202  can include any number of features such as apertures, cavities, indentations, and other mating features to receive and/or attach to one or more components of the device  200 . The electronic device  200  can include internal components such as processors, memory, circuit boards, batteries, and sensors. Such components can be disposed within an internal volume defined, at least partially, by the band  202 , and can be affixed to the band  202 , via internal surfaces, attachment features such as feature  222 , threaded connectors, studs, posts, and/or other fixing features, that are formed into, defined by, or otherwise part of the band  202 . 
     The device  200  can include internal components, such as a system in package (SiP)  226 , including one or more integrated circuits such as a processors, sensors, and memory. The device  200  can also include a battery  224  housed in the internal volume of the device  200 . The device  200  can also include one or more sensors, such as optical or other sensors, that can sense or otherwise detect information regarding the environment exterior to the internal volume of the device  200 . Additional components, such as a haptic engine, can also be included in the device  200 . The electronic device  200  can also include a display assembly  216 , similar to display assembly  116  described herein. In some cases, the display assembly  216  can be received by and/or be attached to the band  202  by one or more attachment features. 
     The electronic device  200  can further include a chassis  220  that can provide structural support. The chassis  220  can include a rigid material, such as a metal, or can include a composite construction, as described herein. Also, the chassis  220  can be coupled to the band  202 . In this manner, the chassis  220  can also provide an electrical grounding path for components electrically coupled to the chassis. The electronic device can alternatively or additionally include a back plate  230  having cladding layers and/or other attachment features such that one or more components of the electronic device  200  can be attached to the back plate  230 , for example, via welding. The back plate  230  can form conductive pathways for connecting components of the electronic device  200 . In some cases, the back plate  230  can be attached to the band  202  of the device  200  by one or more attachment features, such as feature  222 . 
     An exterior surface of the electronic device  200  can further be defined by a back cover  240  that can be coupled to the band  202 . In this regard, the back cover  240  can combine with the band  202  to form an enclosure or housing of the electronic device  200 , with the enclosure or housing (including band  202  and back cover  240 ) at least partially defining an internal volume. The back cover  240  can include a transparent material such as glass, plastic, sapphire, or the like. 
     The housing, including the band  202  having one or more composite components, as described herein, can be conformed to interior dimensional requirements, as defined by the internal components. For example, the structure of the housing including a composite band  202  can be defined or limited exclusively or primarily by the internal components the housing is designed to accommodate. Since a housing with a composite band  202  can be extremely light and strong, the housing can be shaped to house the interior components in a dimensionally efficient manner without being constrained by factors other than the dimensions of the components, such as the need for additional structural elements. The composite components  204 ,  206 ,  208 ,  210  of the band can be formed by a variety of processes, as discussed herein. In some embodiments, these formation processes can allow for the housing and/or band  202  to have a detailed shape or design that is tailored specifically to satisfy one or more needs, such as internal dimensional requirements, without the need for additional features to reinforce the structure of the housing. Additionally, artifacts of the manufacturing process of the housing can be eliminated. 
     Additionally or alternatively, other components of the electronic device  200 , such as individual internal structural components like the chassis  220  or exterior input components, can be formed from or can include a composite component, as described herein. 
     While any number or variety of components of an electronic device, such as electronic device  200 , can be formed from or can include a composite component, the structure of these composite components can be, for example, a composite component including an exterior portion joined to an interior portion, as described herein. The structure and materials of the exterior and interior portion, as well as the composite component itself, can apply to not only to the specific examples discussed herein, but to any number or variety of embodiments in any combination. Various embodiments of composite components are described below, with reference to  FIG.  3   . 
       FIG.  3    shows an exploded view of a band  302  that can form part of a housing or an enclosure of an electronic device, such as electronic device  100  or electronic device  200  described with respect to  FIGS.  1  and  2   . The band  302  can include one or more portions that are composite components or that include composite components, such as an exterior portion joined to an interior portion, as described herein. For example, the band  302  can include a first composite sidewall component  304 , a second composite sidewall component  306 , a third composite sidewall component  308  (opposite the first composite sidewall component  304 ), and a fourth composite sidewall component  310 . In some cases, as described herein, the composite components  304 ,  306 ,  308 ,  310  can be separated and/or joined together by a material that can include an electrically inert or insulating material(s), such as plastics and/or resin, as non-limiting examples. 
     Although the embodiment illustrated in  FIG.  3    includes a band  302  having multiple composite sidewall components  304 ,  306 ,  308 ,  310  that are joined together, in some cases, a housing or enclosure for an electronic device can include or be formed from a single composite component having an interior and exterior portion, as described herein. Further, in some cases, the composite components can form portions of the housing or enclosure other than the sidewalls, such as a top portion, bottom portion, or any portion of the housing or enclosure. Further details of the composite components are provided below with reference to  FIGS.  4 A- 8   . 
       FIG.  4 A  shows an exploded perspective view of a composite component  400  including an outer or exterior portion  402  and an inner or interior portion  404 . Although illustrated in  FIG.  4 A  as an exploded view, the composite component  400  can include an outer or exterior portion  402  that is joined or bonded to the inner or interior portion  404 . In some examples, the exterior portion  402  can be pre-formed and can include a metallic material, such as stainless steel, although other materials are expressly contemplated, as described herein. In some examples, the exterior portion can have a thickness greater than about 25 microns. The interior portion  404  can having a second, different set of material properties that are independent of the first set of material properties of the outer portion  402 . In some examples, the exterior portion  402  and the interior portion  404  can be welded, bonded, adhered, or otherwise joined together such that they form the housing, or a portion thereof, and act as a substantially unitary body  400 . The exterior portion  402  and the interior portion  404  can include any desired shape or design, and thus, the component  400  can include any desired shape or design. In some examples, the component  400  can be a portion of a housing of an electronic device. In some other embodiments, however, the component  400  can be any component of an electronic device, for example, a structural component, internal component, external component, or other similar component. 
       FIG.  4 B  shows an assembled perspective view of a composite component  400 , for example as shown in  FIG.  4 A , including features  412  and  414  formed in and at least partially defined by the interior portion  404 . As can be seen, the features  412 ,  414  can include protruding features, recessed features, or combinations thereof. In some examples, a feature, such as feature  412 , can be formed by an additive manufacturing process. In some examples, a feature, such as feature  414 , can be formed by a subtractive manufacturing process. In some cases, a feature can include an aperture, a recess, a blind hole, a cavity, a protrusion, or combinations thereof. In some examples, a feature  412 ,  414  can be an attachment feature for one or more other components of an electronic device. The component  400  and concepts illustrated in  FIGS.  4 A and  4 B  can be applied to any of the composite components described herein, in any combination. Further examples including the concepts and features discussed with respect to  FIGS.  4 A and  4 B  are described below with reference to  FIGS.  5 - 8   . 
       FIG.  5    shows a composite component  510  that can be similar to or include the features of the composite sidewall components  304 ,  306 ,  308 ,  310  described with respect to  FIG.  3    and the component  400  described with respect to  FIGS.  4 A- 4 B . The composite component  510  can include an outer or exterior portion  522  that is joined to an inner or interior portion  524 . In the present example, the exterior portion  522  can at least partially define an exterior surface of a housing or enclosure of an electronic device. The interior portion  524  can at least partially define a surface of an internal volume of the electronic device. As can be seen in  FIG.  5   , the composite component  510  can include a number of features  532 ,  534 ,  536 , that can, for example, act as attachment features for other components of an electronic device. 
     In some cases, the features can be formed in one or both of the exterior portion  522  and the interior portion  524  of the composite component  510 . For example, the interior portion  524  of the composite component  510  can include a feature, such as aperture  532 . In some cases, the feature  532  can be an aperture, recess, blind hole, or other feature formed in the interior portion  524  by a subtractive process, such as a machining or an etching process. In some examples, the feature  532  can act as an attachment feature for other components of the electronic device. The feature  532  can be configured to receive components of an electronic device, such as buttons or input components. Although depicted as an aperture  532 , the feature  532  can take any form or shape, as desired. In some examples, the feature  532  can extend, at least partially, into the interior portion  524  to a desired depth. Alternatively, however, the feature  532  can extend substantially entirely through an entire thickness of interior portion  524 . 
     In some examples, a feature can be formed in both the exterior portion  522  and the interior portion  524  of the composite component  510 . For example, feature  534  can be formed in, or defined by, both the exterior and the interior portions  522 ,  524  of the component  510 . Feature  534  can be an aperture or a through hole that passes at least partially through the exterior portion  522  and the interior portion  524 . Further, although the portions  522 ,  524  are illustrated as having a relatively uniform thickness, in some examples the thickness of the exterior portion  522  and/or interior portion  524  can vary at locations where features, such as feature  534 , are formed. A protruding feature, such as feature  536 , can be formed in the interior portion  524 , for example, by a machining process or additive manufacturing process, and can serve as an attachment feature for other components of an electronic device. Although depicted as a protrusion defining an aperture therethrough, the feature  536  can include any shape or design, as desired. 
     As described herein, the interior portion  524  of the composite component  510  can be selected such that it has a set of material properties that are desirable for the formation of features, such as features  532 ,  534 ,  536 . For example, the material of the interior portion  524  can be selected to have a material property or set of material properties that allow for the interior portion  524  to be highly machinable without causing high levels of wear on machining tools. Additionally, the material of the interior portion  524  can be relatively inexpensive so that waste material produced by forming the features does not substantially increase production costs. Further, as described herein, the material of the exterior portion can be selected to have a material property or set of material properties, independent of the material properties of the interior portion, that allow the exterior portion  522  to have, for example, high levels of hardness and corrosion resistance. 
     In some examples, the features formed in one or both of exterior portion  522  and interior portion  524 , such as features  532 ,  534 ,  536 , can have a major dimension from about a micron up to about a millimeter, or several millimeters or more. In some cases, a feature, such as feature  536  can have a major dimension from about 100 microns to about 1 millimeter. Further, in some examples, a feature, such as feature  536 , can have minor dimensions from about 100 microns to about 1 millimeter. 
     Further, as can be seen in  FIG.  5   , the exterior portion  522  can have a substantially curved shape or profile that can correspond to an exterior profile of the electronic device. The exterior portion  522  can have any shape or profile, as desired. In some examples where the exterior portion has a substantially curved shape or profile, the interior portion  524  can be positioned entirely behind or within a curve defining the curved profile of the exterior portion  522 . Additional details of the exterior portion  522  are provided below with reference to  FIG.  6   . 
       FIG.  6    shows another perspective view of the composite component  510  of the housing of  FIG.  5   . As can be seen in  FIG.  6   , one or more areas, such as area  538 , of the exterior portion  522 , can be removed so that at least some of the interior portion  524  can be exposed. The exposed surface of the interior portion  522  can be subjected to a treatment or other processing in order to, for example, protect the exposed surface of the interior portion  522 . In some examples, the exterior portion  522  can include a stainless steel alloy and the interior portion  524  can include aluminum. At area  538 , where the aluminum of the interior portion  524  is externally exposed, an interface between the stainless steel of the exterior portion  522  and the aluminum of the interior portion  524  can also be exposed. 
     In such cases, the interface between the materials of the two portions can form a galvanic contact and one of the materials of the portions  522 ,  524  can be subjected or prone to galvanic corrosion. Accordingly, areas, such as area  538 , where an interface between the materials of the portions  522 ,  524  is exposed can be processed or treated to prevent or inhibit galvanic corrosion. A material or materials can be deposited over the interface between the portions  522 ,  524  at area  538  to prevent or inhibit galvanic corrosion. Example material can include, but are in no way limited to, a polymeric material, a metallic material, a ceramic material, or combinations thereof. 
     Alternatively, the geometry of the exterior portion  522  and/or interior portion  524  can be designed so that an interface between the portions is not exposed, even when features such as feature  538  are formed in the exterior portion  522 . For example, in some cases, the exterior portion  522  can be thicker at the area  538  where a feature is formed so that the interior portion  524  is not exposed, even when material is removed from the exterior portion  524 . The interior portion  524  can correspondingly be made thinner at areas where the exterior portion  522  has an increased thickness, so that the composite component  510  maintains a relatively uniform thickness. Alternative views and features of the composite component  510  are detailed below, with reference to  FIGS.  7  and  8   . 
       FIG.  7    shows a top view of the composite component  510  depicted in  FIGS.  5  and  6   . As can be seen, the thicknesses of one or both of the exterior portion  522  and the interior portion  524  can have a thickness that varies along the length of the component  510 . Alternatively, however, the thickness of the exterior portion  522  and/or interior portion  524  can be substantially uniform along the length of the component  510 . The exterior portion  522  can have a thickness of greater than about 25 microns, greater than about 50 microns, greater than about 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, or greater. In some examples, the exterior portion can have a thickness of up to about 1 millimeter, up to about 2 millimeters, or up to about 5 millimeters or more. In alternative examples, the interior portion  524  can have any desired thickness or thicknesses. For example, as shown in  FIG.  7   , the interior portion  524  can have a thickness that varies from about 100 microns up to about several millimeters or more. In some instances, the interior portion can have a thickness that approximates an entire width of the electronic device. 
       FIG.  8    shows a side view of the composite component  510  depicted in  FIGS.  5 - 7   . As described herein, the interior portion  524  can include any number of features that are formed in the material or the interior portion  524 , or added or attached to the interior portion  524  by any desired method or process. In some cases, the features, such as feature  534 , can serve as attachment features for components of an electronic device, such as an internal component or structural components. Further, in some examples, the interior portion  524  can form or define a surface that at least partially defines an internal volume of an electronic device. In some examples, the exterior portion  522  may not form part of a surface that defines an internal volume of an electronic device. In some instances, however, the exterior portion  522  can form at least part of a surface that defines an internal volume of an electronic device. 
     While any number or variety of components of an electronic device can be formed from or can include a composite component, such as component  210 ,  310 ,  400 , and/or  510  detailed above, the structure of these composite components typically includes an exterior portion joined to an interior portion, as described herein. The structure and materials of the exterior and interior portions, as well as the composite component itself, can apply not only to the specific examples discussed herein, but also to any number or variety of embodiments in any combination. Various exemplary features of a composite component are described below with reference to  FIGS.  9 A- 11   . 
       FIG.  9 A  shows a perspective view of a composite component  600  including an exterior portion  602  bonded to an interior portion  604 , as described herein. In some examples, the exterior portion  602  can include a metal material, although other materials are expressly contemplated, as described herein. The interior portion can include a second material different than the material of the exterior portion, and including a second set of material properties, independent of the set of material properties of the exterior portion  602 . As can be seen in  FIG.  9 A , the exterior portion  602  and the interior portion  604  can cooperate to at least partially define a feature  612 . In some examples, the feature  612  can be a recess, an aperture, a cavity, or other similar features, as shown. In some other examples, however, the feature  612  can include a protrusion or positive feature, or combinations thereof. Such a feature  612  can be, in some examples, an attachment feature for joining the component  600  to one or mother other components of an electronic device. 
       FIG.  9 B  shows a perspective simplified view of a composite component  700 , including an exterior portion  702  bonded to an interior portion  704 , as described herein. As can be seen, the composite component  700  also includes an intermediate layer  706  disposed between the exterior portion  702  and the interior portion  704  that can at least partially bond the portions  702 ,  704  together. In some examples, the intermediate layer  706  can have any thickness and can be any desired material, such as a polymeric material. In some examples, the intermediate layer  706  can include a heat activated film, an adhesive, a polymer, a resin or epoxy, and the like. In some cases, features, such as feature  712 , can be formed in the exterior and/or interior portions  702 ,  704  prior to joining the portions  702 ,  704  via the intermediate layer  706 . In some other examples, however, the portions  702 ,  704  can be joined by the intermediate layer  706  and then one or more features, such as feature  712 , can be formed in the component  700 . 
     The components  600  and  700  and concepts illustrated in  FIGS.  9 A and  9 B  can be applied to any of the composite components described herein, in any combination. Further cases including the concepts and features discussed with respect to  FIGS.  9 A and  9 B  are described below, with reference to  FIGS.  10 - 11   . 
       FIG.  10    shows a close-up perspective view of a composite component  810  that can form a part of a housing or an enclosure of an electronic device. As with component  510  depicted in  FIGS.  5 - 8   , the component  810  can include a pre-formed exterior portion  822  that is joined to an interior portion  824 . The exterior portion  822  can include a material or materials having a first set of material properties, while the interior portion  824  can include a material or materials having a second set of material properties independent of the first set of material properties. 
     As described herein, in some examples, the exterior portion  822  can be directly joined, bonded, or adhered to the interior portion  824 . That is, the exterior portion  822  can directly contact, abut, be fused to, bonded to, or otherwise joined to the interior portion  824 . In some examples where the exterior portion  822  and interior portion  824  both include metal materials, the bond between the exterior and interior portions  822 ,  824  can be a metallurgical bond. In some examples, the exterior portion  822  can directly contact the interior portion  824  along substantially the entire interface, or only at one or more locations. Further, in some embodiments, even where the portions  822 ,  824  are in direct contact along substantially the entire interface, the portions  822 ,  824  can be bonded or joined together at only one or more locations. For example, the interior portion  824  can, in some embodiments, be welded to the exterior portion  822  at one or more locations. 
     The interior portion  824  can be joined to the exterior portion  822  by any number of processes such as brazing, diffusion bonding, electron beam welding, ultrasonic welding, laser welding, and other joining methods. In some examples, the portions  822 ,  824  can be welded together by a pulsed laser welding process, such as a nanosecond pulsed laser welding process. In examples where a welding process is used, the welding process can be conducted along the interface or seam between the portions  822 ,  824 , or can be conducted through one or both of the portions  822 ,  824  at any number of desired locations. 
     As can be further seen in  FIG.  10   , the composite component  810  can include one or more features, such as feature  832 , that are formed from or defined by both the exterior portion  822  and interior portion  824 . In some instances, feature  832  can be an attachment feature, for example for one or more components of an electronic device. Feature  832  can also serve alternative or additional purposes and can, for example, serve to reduce the weight of the composite component  810 . In some examples, a feature  832  can facilitate the joining of the composite component  810  to another composite component to form a housing or an enclosure, such as band  102  or  202 , as described herein. In some examples, feature  832  can mechanically engage with a material, such as material  114 ,  214 ,  314  described herein, to form a band  102 ,  202 . 
     While any number or variety of components of an electronic device can be formed from or can include a composite component, such as component  210 ,  310 ,  400 ,  510 ,  600 , and/or  810 , the structure of these composite components can be, for example, a composite component including an exterior portion joined to an interior portion, as described herein. The structure and materials of the exterior and interior portion, as well as the composite component itself, can apply not only to the specific examples discussed herein, but to any number or variety of embodiments in any combination. Various embodiments of composite components are described below with reference to  FIG.  11   . 
       FIG.  11    shows an exemplary composite component  910  that can include a pre-formed exterior portion  922  joined to an interior portion  924  by an intermediate layer  926 . The intermediate layer  926  can include any desired material, such as a polymeric material, ceramic material, metallic material, or combinations thereof. In some examples, the intermediate layer  926  can include a heat activated film, an adhesive material, an injection molded material such as an injection molded metal or polymer material, and similar joining materials. In some examples, the intermediate layer  926  can include a resin or epoxy that can be cured to bond the exterior portion  922  to the interior portion  924 . The intermediate layer can also include a moldable material, such as a polymeric material, that can be provided between the portions  922 ,  924  in a moldable form and cured or cooled to thereby bond the portions  922 ,  924  together. 
     The intermediate layer  926  can have any desired thickness. In some examples, the intermediate layer can have a thickness up to about 1 micron or smaller, about 5 microns, about 10 microns, about 50 microns, about 100 microns, about 200 microns, about 300 microns, about 500 microns, about 0.1 millimeters, about 0.5 millimeters, about 1 millimeter, about 2 millimeters, or about 5 millimeters or more. In some examples, one or more surfaces of the exterior portion  922  and/or interior portion  924  can include features that can mechanically engage with the intermediate layer  926 , for example, to bond the portions together. For example, a surface of the exterior portion  922  and/or interior portion  924  can include nano-scale, micro-scale, or macro-scale features that mechanically engage with the intermediate layer  926 . These features can be formed by treating a surface of the portion  922 ,  924 , for example, by machining, etching, and similar surface treatments. 
     In some examples, as discussed herein, where the exterior portion  922  and the interior portion  924  can include materials that can be susceptible to galvanic corrosion, such as steel and aluminum, an intermediate layer  926  can serve to inhibit or prevent such corrosion, for example, by preventing the direct contact of the portions  922 ,  924  in at least some locations. In some examples, the intermediate layer  926  can be present at or along an entire interface between the exterior portion  922  and the interior portion  924 . In other examples, however, the intermediate layer  926  may only be present at one or more locations between the portions  922 ,  924 , such as, at locations where the interface between the exterior portion  922  and the interior portion  924  is exposed to, or can be exposed to an external environment. 
     The exterior portion  922  and interior portion  924  of a composite component  910  including an intermediate layer  926  can additionally or alternatively be joined or bonded by other methods as described herein. For example, the exterior portion  922  can be joined with the interior portion  924  by mechanical engagement with the intermediate layer  926  at one or more locations and by welding at one or more other locations. 
     While any number or variety of components of an electronic device can be formed from or can include a composite component, such as component  210 ,  310 ,  400 ,  510 , and/or  810 , the structure of these composite components can be a composite component including an exterior portion joined to an interior portion, as described herein. The structure and materials of the exterior and interior portion, as well as the composite component itself can apply not only to the specific examples discussed herein, but to any number or variety of embodiments in any combination. Various embodiments of composite components are described below with reference to  FIGS.  12 - 14   . 
       FIG.  12 A  shows an exploded simplified view of a composite component  1000  including an exterior portion  1002  and an interior portion  1004 . As described herein, the exterior portion can include a first material, such as a metal, and can be pre-formed. The interior portion  1004  can at least partially define a feature or features  1012 ,  1014  and, as illustrated, can include two or more layers  1022 ,  1024 .  1026 ,  1028 . In some examples, these layers  1022 - 1028  can include or be formed from a single material, which can include any of the materials described herein as forming the interior portion generally. Alternatively, however, one or more of the layers  1022 - 1028  can include a different material than another layer. For example, layer  1022  can include a second material that is different than the first material of the exterior portion  1002 , while layer  1024  can include a third material that is different than the first material of the exterior portion  1002  and the second material of layer  1022 . The layers  1022 - 1028  of the interior portion  1004  can be bonded to one another by any of the methods described herein with respect to bonding portions together, for example, welding, brazing, diffusion bonding, adhesives, mechanical engagement, and other similar bonding or joining methodologies. Although depicted in a substantially horizontal stack, the layers  1022 - 1028  can be arranged to form the interior portion  1004  in any desired manner. For example, the layers can be stacked vertically, horizontally, or any angle in between. 
     As can be seen in  FIG.  12 B , the layers  1022 - 1028  can cooperate to form and define the interior portion  1004  of the component  1000 . Further, two or more layers  1024 ,  1026  can cooperate to form or define one or more features  1012 ,  1014 . In some examples, the feature  1012  can be a recess, aperture, cavity, or the like as shown. In some other examples, however, the feature  1014  can include a protrusion or positive feature, or combinations thereof. Such a features  1012 ,  1014  can be an attachment feature for joining the component  1000  to one or more other components of an electronic device. In some examples, the layers  1022 - 1028  can be shaped or formed into a desired shape prior to being bonded together to define the features  1012 ,  1014 . In some other cases, however, the layers  1022 - 1028  can be bonded or joined together and can then be subjected to additive or subtractive processing to form one or more features  1012 ,  1014  therein. 
     The component  1000  and concepts illustrated in  FIGS.  12 A and  12 B  can be applied to any of the composite components described herein, in any combination. Further examples including the concepts and features discussed with respect to  FIGS.  12 A and  12 B  are described below with reference to  FIGS.  13  and  14   . 
       FIG.  13    illustrates a composite component  1110  that can be or form part of an enclosure or housing, such as band  102 ,  202  described herein. The composite component  1110  can include an outer or exterior portion  1122  that is joined to an inner or interior portion  1124 , as described herein. The exterior portion  1122  can at least partially define an exterior surface of a housing or an enclosure of an electronic device. In the present example, the interior portion  1124  can at least partially define a surface that defines an internal volume of the electronic device and can include or be formed from one or more layers  1141 ,  1142 . 
     As can be seen in  FIG.  13   , the interior portion  1124  having two or more layers  1141 ,  1142  can include features, such as feature  1132 , which can serve as attachment features for other components of an electronic device. As illustrated in  FIG.  13   , two or more layers  1141 ,  1142  can cooperate to form features in the interior portion  1124 , such as feature  1132 . In some examples, a feature  1132  can be formed in the interior portion  1124  subsequent to joining two or more layers  1141 ,  1142  together, for example, by machining. Alternatively, layers  1141 ,  1142  can be shaped prior to joining, so as to define a feature  1132  upon being joined. In those cases where layers  1141 ,  1142  can be shaped prior to joining to form a feature  1132 , the interior portion  1124  and/or feature  1132  can be subjected to treatment or processing to further define the shape of the feature. Further details of how multiple layers may be joined to form the interior portion  1124  and provided below with reference to  FIG.  11   . 
     Turning now to  FIG.  14   , an exploded view of interior portion  1124  including the layers  1141 ,  1142 ,  1143 ,  1144 ,  1145 ,  1146 ,  1147 ,  1148 ,  1149 , and  1150  that make up the portion  1124  is illustrated. In some examples, the layers  1141 - 1150  can include or be formed from a single material, which can include any of the materials described herein as forming the interior portion generally. Alternatively, however, one or more of the layers  1141 - 1150  can include a different material than the other layers  1141 - 1150 . For example, layers  1141 ,  1143 ,  1145 ,  1147 ,  1149  can include a first material, such as a metallic material, while layers  1142 ,  1144 ,  1146 ,  1148 ,  1150  can include a second, different material, such as a polymeric material. Other configurations of layers and materials are expressly contemplated. The layers  1141 - 1150  can be joined or bonded to one another by any method or process described herein in the context of joining an exterior portion to an interior portion to form a substantially unitary interior portion  1124 . For example, a layer  1141  can be directly welded to an adjacent layer  1142 , or the layers  1141 ,  1142  can be joined together by an intermediate material, such as an adhesive or heat activated film. 
     In some examples, one or more of the layers  1141 - 1150  can be formed into a desired shape or design prior to being joined to another layer, to form the interior portion  1124 . For example, a layer  1144  can include a metallic material, such as aluminum, and can be formed by stamping a sheet of aluminum having the desired layer thickness. This stamped layer  1144  can then be joined or bonded to one or more adjacent layers,  1143 ,  1145  to form the interior portion  1124 . As described above with respect to  FIG.  13   , the layers  1141 - 1150  can cooperate to form or define a feature  1132 . Alternatively, a feature  1162  can be formed in or defined by an individual layer, such as layer  1145 . 
     One or more of layers  1141 - 1150  can be substantially continuous or unitary. In some instances, however, one or more of layers  1141 - 1150 , such as layer  1145 , may not be continuous and can include two or more disconnected or discontinuous parts or pieces. In some instances, an underlying layer, such as layer  1146  can serve to hold or maintain the parts or pieces of discontinuous layer  1145  in a desired position or orientation. 
     One or more of layers  1141 - 1150  can have substantially the same thickness or height as one or more other layers of layers  1141 - 1150 . In some examples, however, one or more of the layers  1141 - 1150  can have a different thickness than one or more other layers  1141 - 1150 . Each layer  1141 - 1150  can have any desired thickness, for example, up to about 10 microns, about 25 microns, about 50 microns, about 100 microns, about 200 microns, about 300 microns, about 400 microns, about 500 microns, or greater. In some examples, a layer  1141 - 1150  can have a thickness of about 1 millimeter, about 2 millimeters, or greater. 
     Although the layers  1141 - 1150  are illustrated in an orientation where the width of an individual layer substantially corresponds to a width of the interior portion  1124  while the thickness of an individual layer makes up only a fraction of the height of the interior portion  1124 , in some cases, the layers  1141 - 1150  can be disposed, shaped, or joined in any number of orientations. For example, the height of an individual layer can substantially correspond to a height of the interior portion  1124  while the width of an individual layer can make up only a fraction of the width of the interior portion  1124 . Alternatively, the layers  1141 - 1150  can be shaped and/or joined such that a width, height, and/or length of a layer can make up only a fraction of the width, height, and/or length of the interior portion  1124 . 
     While any number or variety of components of an electronic device can be formed from or can include a composite component, such as component  210 ,  310 ,  400 ,  510 ,  600 ,  700 ,  810 ,  910 , and/or  1110 , the structure of these composite components can include an exterior portion joined to an interior portion, as described herein. The structure and materials of the exterior and interior portion, as well as the composite component itself, can apply not only to the specific examples discussed herein, but to any number or variety of embodiments in any combination. Various embodiments relating to methods and processes for forming the presently described structures are described below with reference to  FIGS.  15 - 18   . 
       FIG.  15    illustrates a process flow diagram of an exemplary process for forming a composite component, as described herein. The process  1200  for forming the composite component can include joining a pre-formed portion, such as an exterior portion as described herein, including a first material having a first material property or set of material properties, with a second portion, such as an interior portion as described herein, including a second material having a second material property or set of material properties, at block  1210 . Once joined, the process continues by forming one or more features in at least the second portion, at block  1220 . 
     At block  1210 , a pre-formed first portion, can be joined with a second portion. The pre-formed first portion can include a first material, while the second portion can include a second material that can be independently selected. The materials of the first and second portions can include any of the materials described herein with respect to interior and/or exterior portions of a composite component. In some examples, the pre-formed first portion can be subject to treatment or processing prior to joining, for example, to form a desired profile or shape, or to form one or more features therein. 
     In some examples, the pre-formed first portion can be positioned or held in a desired position, for example by a clamping device or other apparatus, and the second portion can be brought into contact with the pre-formed first portion, whereupon the portions are joined together to form a substantially unitary body. The particular process used to join the portions can include any of the processes discussed herein and can be selected depending on the materials of the pre-formed first portion and the second portion. For example, joining can include directly joining the pre-formed first portion with the second portion via processes such as welding, for example ultrasonic welding or laser welding, brazing, diffusion bonding, fusing, or other similar methods. In some examples, joining can include pulsed laser welding, for example nanosecond pulsed laser welding. Alternatively, joining can include mechanically engaging a feature of the pre-formed first portion with a corresponding feature of the second portion, as described herein. 
     In some examples, joining can alternatively or additionally include providing a layer or material between the pre-formed first portion and the second portion to join the portions together. Thus, in some examples, joining can include providing a material such as an adhesive, a glue, a heat activated film, a polymer material such as epoxy or resin, or another moldable material between the pre-formed first portion and the second portion. This intermediate layer can be provided as a moldable material between the portions, in at least some locations, and cured or cooled to join the portions. In some instances, the intermediate material can form a direct bond with the surface of one or both portions, such as a chemical or metallurgical bond. In some examples, the intermediate material can join the portions by alternatively or additionally mechanically engaging with one or more features on a surface of the portions. 
     In some examples, the second portion can be joined with the pre-formed first portion by providing the second portion to the pre-formed first portion in a moldable form and curing, cooling, or otherwise hardening the material of the second portion. For example, the second portion can be cast, die cast, molded, injection molded, metal injection molded, or otherwise formed into a feature or features of the pre-formed first portion. In some examples, the pre-formed first portion can be present in a mold or other apparatus and the second portion can be provided into the mold to solidify and join with the pre-formed first portion. 
     In some examples, providing the second portion in moldable form can join the pre-formed first portion and second portion by forming a bond directly between the materials of the first and second portions, such as a chemical or a metallurgical bond. The portions can alternatively or additionally be joined by mechanical engagement between the material of the second portion with one or more features formed in or on a surface of the first portion, such as nano-, micro-, and/or macro-scaled features. Thus, in some examples, material of the second portion can flow or otherwise be provided into one or more receiving features of the pre-formed first portion and solidify to thereby mechanically engage with and join the portions. 
     Further, the first portion, although described as a pre-formed first portion, can be formed substantially simultaneously with the second portion. For example, in some cases, the first and second portions can be co-extruded or can both be provided in moldable form so that the portions are joined by a chemical bond, a metallurgical bond, a mechanical engagement, other joining functionalities, or combinations thereof. 
     At block  1220 , one or more features are formed in at least the second portion of the composite component. The feature or features can be formed according to any of the processes or methods described herein, such as additive or subtractive manufacturing processes. For example, one or more features can be formed in at least the second portion by machining, etching, depositing, molding, or other processes. Alternatively, the one or more features can be formed in both the pre-formed first portion and the second portion, for example, as described herein. 
     Forming one or more features in at least the second component at block  1220  can occur substantially simultaneously with the joining step at block  1210 . For example, in some cases where the second portion can be cast or molded into the pre-formed first portion, the one or more features can be formed in the second portion during the molding or casting process when the second portion is solidified or otherwise formed and joined with the first portion. The formed composite component can be subjected to further processing and treatment, as described herein. For example, an exterior surface of the pre-formed first portion can be treated, for example by depositing a PVD layer thereon, to provide a desired color or surface finish. 
       FIGS.  16  and  17    illustrate examples of a unitary body  1300 ,  1400  including a pre-formed first portion  1322 ,  1422  joined with a second portion  1324 ,  1424 , as described above with respect to method  1200 . As can be seen in  FIG.  16   , the pre-formed first portion  1322  can be directly joined with the second portion. Further, in some cases, the pre-formed first portion can have a non-rectangular profile and can have, for example, a curved profile corresponding substantially to a desired final profile of the composite component. As shown in  FIG.  17   , an intermediate layer  1426  can be present between the pre-formed first portion  1022  and the second portion  1424 , as described herein. 
     The unitary bodies  1300 ,  1400  illustrated in  FIGS.  16  and  17    have not yet had any features formed thereon, as detailed in block  1220 . In some examples, the unitary bodies  1300 ,  1400  can be processed in an essentially similar manner and by essentially similar equipment and apparatuses as a unitary piece of material to form a composite component. For example, the composite unitary body  1300 ,  1400  can be machined by a machining apparatus that can generally be used to machine parts out of a body of a single material. 
       FIG.  18    illustrates a schematic diagram depicting process steps for the method  1200  described above, including die casting the second portion  1524  onto the pre-formed first portion  1522 . Pre-formed first portion  1522  can be initially provided or formed in any general shape or configuration. As described above, the pre-formed portion  1522  can be subjected to treatment or processing to, for example, provide a desired exterior profile to the portion. As illustrated in  FIG.  18   , this includes machining or otherwise removing material from the portion to achieve a desired curved profile. Further, as described above with respect to  FIG.  14    and method  1200 , the second portion can be provided in a moldable form adjacent to the first portion and solidified to thereby join the first and second portions, for example by die casting or metal injection molding. In some examples, the casting or molding process can also form one or more features  1532  in at least the second portion substantially simultaneous with the joining step. The joined composite unitary body can then be subjected to further processing, as described herein, for example, to provide a surface treatment or treatments, or to further define or form features in the first and/or second portion. 
     Any of the features or aspects of the composite components discussed herein can be combined or included in any varied combination. For example, the design and shape of the exterior or first portion and the interior or second portion is not limited in any way and can be formed by any number of processes, including those discussed herein. Further, a first portion can be joined with a second portion at any time and by any known method, even during formation of one or both portions. A composite component, as discussed herein, can be or can form all or a portion of a component, such as a housing or enclosure, for an electronic device. The composite component can also be or form any number of additional components of an electronic device, including internal components, external components, cases, surfaces, or partial surfaces. 
     As used herein, the terms exterior, outer, interior, and inner are used for reference purposes only. An exterior or outer portion of a composite component can form a portion of an exterior surface of the component, but may not necessarily form the entire exterior of outer surface thereof. Similarly, the interior or inner portion of a composite component can form or define an interior or inner portion of the component, but can also form or define a portion of an exterior or outer surface of the component. 
     Various inventions have been described herein with reference to certain specific embodiments and examples. However, they will be recognized by those skilled in the art that many variations are possible without departing from the scope and spirit of the inventions disclosed herein, in that those inventions set forth in the claims below are intended to cover all variations and modifications of the inventions disclosed without departing from the spirit of the inventions. The terms “including:” and “having” come as used in the specification and claims shall have the same meaning as the term “comprising.” 
     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 target 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: 20190621
Publication Date: 20241008
Grant Date: 20241008
Priority Date: 20190129
Inventors: COUNTS, WILLIAM A.
MESCHKE, ANDREW W.
GAO, LEI
MISRA, ABHIJEET
WILLIAMS, ALEXANDER W.
LI, HOISHUN
HOOTON, LEE E.
WITTENBERG, MICHAEL B.
YURKO, JAMES A.
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K5/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F2200/1633", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K5/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0213", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0283", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0213", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/04", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/0202", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K5/0217", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F2200/1633", "inventive": false, "first": false, "tree": "[]"}, {"code": "A45C2011/002", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K5/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0213", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0004", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0283", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "A45C11/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/04", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 71733012