PATENT DOCUMENT

Publication Number: US-11418638-B2
Application Number: US-201916569525-A
Country: US
Kind Code: B2

Title: Electronic device having a composite structure

Abstract:
Embodiments are directed to an enclosure for an electronic device. In one aspect, an embodiment includes an enclosure having an enclosure component and an internal component that may be affixed along a bonding region. The enclosure component may be formed from an enclosure material and defines an exterior surface of the enclosure and an opening configured to receive a display. The internal component may be formed from a metal material different than the enclosure material. The bonding region may include an interstitial material that has a melting temperature that is less than a melting temperature of either one of the enclosure material or the metal material. The bonding region may also include one or more of the enclosure material or the metal material.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 an enclosure comprising:
 an aluminum rear wall defining a rear exterior surface and an interior surface of the enclosure opposite to the rear exterior surface; and 
 a set of sidewalls extending from the aluminum rear wall and surrounding the interior surface of the enclosure; 
 one or more ribs arranged along a portion of the interior surface, the one or more ribs in combination with the set of sidewalls at least partly defining a compartment on the interior surface of the aluminum rear wall; 
 a set of mounting features formed from steel, each mounting feature defining a threaded aperture, the set of mounting features extending from a portion of the interior surface located within the compartment; 
 a first bonding layer disposed between each mounting feature of the set of mounting features and the aluminum rear wall and bonding each mounting feature to the interior surface of the aluminum rear wall, the first bonding layer comprising: 
 an interstitial material that has a melting temperature less than that of the steel, the interstitial material being one of nickel, a nickel alloy, zinc, a zinc alloy, or an aluminum alloy; and 
 aluminum from the aluminum rear wall melted together with the interstitial material; 
 
 a circuit assembly positioned over the set of mounting features and defining a set of openings; and 
 a set of threaded fasteners, each threaded fastener of the set of threaded fasteners extending through an opening of the set of openings in the circuit assembly and into a threaded aperture of a respective mounting feature of the set of mounting features, thereby securing the circuit assembly to the enclosure. 
 
     
     
       2. The electronic device of  claim 1 , wherein:
 the electronic device is a laptop computer; 
 the electronic device further comprises:
 a display coupled to the enclosure and configured to produce graphical outputs; and 
 an input system coupled to the enclosure and configured to receive inputs from a user; 
 
 the input system comprises a keyboard; and 
 the display is pivotally coupled to the enclosure. 
 
     
     
       3. The electronic device of  claim 1 , wherein:
 the one or more ribs are formed of steel; further comprising: 
 a second bonding layer disposed between the one or more ribs and the aluminum rear wall and bonding each rib of the one or more ribs to the interior surface of the aluminum rear wall, the second bonding layer comprising:
 the interstitial material; and 
 aluminum from the aluminum rear wall melted together with the interstitial material. 
 
 
     
     
       4. The electronic device of  claim 3 , wherein:
 a rib of the one or more ribs defines a passage between the rib and the interior surface; and 
 the electronic device further comprises an electrical connector extending through the passage. 
 
     
     
       5. The electronic device of  claim 4 , wherein:
 the compartment is a first compartment; 
 the circuit assembly is a first circuit assembly; 
 the one or more ribs further define at least a portion of a second compartment; 
 the electronic device further comprises:
 a second circuit assembly positioned at least partially in the second compartment; and 
 
 the electrical connector electrically couples the first circuit assembly to the second circuit assembly. 
 
     
     
       6. The electronic device of  claim 1 , wherein the set of sidewalls is formed of aluminum. 
     
     
       7. The electronic device of  claim 1 , wherein the one or more ribs comprise steel.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/606,920, filed May 26, 2017, and entitled “Electronic Device Having a Composite Structure,” which claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 62/397,781, filed on Sep. 21, 2016, and entitled “Aluminum-Steel Composite,” the contents of which are incorporated by reference as if fully disclosed. 
    
    
     FIELD 
     The described embodiments relate generally to an electronic device having two dissimilar materials joined along a bonding region. More particularly, the present embodiments relate to joining dissimilar metals and/or a metal component and a ceramic component via an interstitial material to form an electronic device enclosure. 
     BACKGROUND 
     Dissimilar materials may be joined together to form an electronic device enclosure or other composite structure. The composite structure may exhibit material properties of one or both of the materials. For dissimilar metals, such composites may be susceptible to brittle fracture or other failure modes at a joint or bonding region between the dissimilar materials. For example, directly joining (e.g., welding) dissimilar metals having different melting temperatures, electrical or thermal conductivities, and/or tensile strengths may contribute to the production of brittle intermetallic compounds. 
     SUMMARY 
     Embodiments of the present invention are directed to an electronic device enclosure and methods for forming the same. 
     In a first aspect, the present disclosure includes an enclosure for an electronic device. The enclosure includes an enclosure component formed from an enclosure material. The enclosure component may define an exterior surface of the enclosure and an opening configured to receive a display. The enclosure further includes an internal component formed from a metal material that may be different than the enclosure material and affixed to the enclosure component along a bonding region. The bonding region may include an interstitial material that has a melting temperature less than a melting temperature of either one of the enclosure material or the metal material. The bonding region may also include one or more of the enclosure material or the metal material. 
     A number of feature refinements and additional features are applicable in the first aspect and contemplated in light of the present disclosure. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature combination of the first aspect. 
     For example, in an embodiment, the bonding region includes a blended melt layer formed from the interstitial material and the one or more of the enclosure material or the metal material. The blended melt layer may be affixed to both of the enclosure component and the internal component. In some cases, the enclosure material may be aluminum and the metal material may be steel. In other cases, the enclosure material may be a ceramic and the metal material may be steel. 
     In another embodiment, the interstitial material may include at least one of nickel, zinc, or aluminum alloy. The enclosure may be configured to receive a printed circuit board (PCB). In this regard, the internal component may be configured to electrically conduct a signal received from the PCB. Additionally or alternatively, the internal component may form an electrical shield along an interior surface of the enclosure. 
     In this regard, a second aspect of the present disclosure includes a method of manufacturing a device enclosure. The method includes abutting an enclosure component and an internal component along a bonding region. The method further includes affixing the enclosure component to the internal component by heating the bonding region to a temperature that is less than a melting temperature of one of the enclosure component or the internal component. The internal component may include a interstitial material at the bonding region. The interstitial material and the enclosure component may form a blended melt layer within the bonding region in response to the heating. 
     A number of feature refinements and additional features are applicable in the second aspect and contemplated in light of the present disclosure. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature combination of the second aspect. 
     For example, in an embodiment, the internal component may define a threaded feature. In this regard, the method may further include attaching a printed circuit board (PCB) to the enclosure component by advancing a fastener through the PCB and into the threaded feature. Additionally or alternatively, the method may further include anodizing at least one of the enclosure component or the internal component prior to affixing the enclosure component and the internal component. 
     According to another embodiment, the interstitial material may include one of nickel, zinc, or aluminum alloy. The interstitial material may coat the internal component prior to affixing the enclosure component and the internal component. In some cases, the interstitial material may be a first interstitial material and the enclosure component may include a second interstitial material at the bonding region. The first and second interstitial materials and the enclosure component may form the blended melt layer within the bonding region in response to the heating. 
     In another embodiment, affixing the enclosure component and the internal component may further include compressing the enclosure component and the internal component. Additionally or alternatively, heating the bonding region may further include applying an ultrasonic vibration to at least one of the enclosure component and the internal component. 
     In this regard, a third aspect of the present disclosure includes an enclosure for an electronic device. The enclosure includes an enclosure component formed from an enclosure material and having sidewalls that define an internal volume and a top surface that defines an opening configured to receive a touch-sensitive display. The enclosure further includes a structural member formed from a steel-based material. The enclosure further includes a first interstitial material affixed to a surface of the enclosure component. The enclosure further includes a second interstitial material affixed to a surface of the structural member. A portion of the first and second interstitial materials form a blended melt layer joining the enclosure component and the structural member within the internal volume of the enclosure. A melting temperature of each of the first and second interstitial materials is less than a melting temperature of the steel-based material. 
     A number of feature refinements and additional features are applicable in the third aspect and contemplated in light of the present disclosure. These feature refinements and additional features may be used individually or in any combination. As such, each of the following features that will be discussed may be, but are not required to be, used with any other feature combination of the third aspect. 
     For example, in an embodiment, the blended melt layer may be formed from at least a portion of the enclosure component. In some cases, the structural member may define a threaded feature. The structural member may be configured to secure a printed circuit board (PCB) to the enclosure component by receiving a threaded fastener that extends through the PCB. The PCB may include a processing unit configured to control a function of the electronic device. 
     According to another embodiment, the structural member may be a rib extending between the sidewalls of the enclosure. The rib may be configured to provide rigidity to an exterior surface of the enclosure. The rib may separate the internal volume into discrete compartments. One of the discrete compartments may be configured to receive a printed circuit board (PCB). The rib may define a passage configured to receive a set of wires extending from the PCB and between the discrete compartments of the internal volume. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following description. 
    
    
     
       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  depicts a sample electronic device including a composite structure; 
         FIG. 2  depicts a cross-sectional view of the embodiment of the electronic device of  FIG. 1 , taken along line A-A of  FIG. 1 ; 
         FIG. 3  depicts a cross-sectional view of the embodiment of the electronic device of  FIG. 1 , taken along line B-B of  FIG. 1 ; 
         FIG. 4A  depicts an enclosure component having a first interstitial material and an internal component having a second interstitial material; 
         FIG. 4B  depicts a composite structure including the enclosure component and the internal component of  FIG. 4A  and having a blended melt layer; 
         FIG. 4C  depicts an enlarged view of the composite structure of  FIG. 4B ; 
         FIG. 5A  depicts an enclosure component and an internal component having interstitial sheets positioned therebetween; 
         FIG. 5B  depicts a composite structure including the enclosure component and the internal component of  FIG. 5A  and having a blended melt layer; 
         FIG. 6A  depicts an enclosure component and an internal component having a interstitial material; 
         FIG. 6B  depicts a composite structure including the enclosure component and the internal component of  FIG. 6A  and having a blended melt layer; 
         FIG. 7  depicts a sample bonding tool rotating an internal component to form a bond between the internal component and an enclosure component; 
         FIG. 8A  depicts another embodiment of a sample electronic device including a composite structure; 
         FIG. 8B  depicts an exploded view of the sample electronic device of  FIG. 8A ; 
         FIG. 8C  depicts an enlarged view of the composite structure of  FIG. 8B ; 
         FIG. 9A  depicts another embodiment of a sample electronic device including a composite structure; 
         FIG. 9B  depicts an exploded view of the sample electronic device of  FIG. 9A ; 
         FIG. 9C  depicts an enlarged view of the composite structure of  FIG. 9B ; 
         FIG. 9D  depicts an enlarged view of another embodiment of the composite structure of  FIG. 9B ; 
         FIG. 10A  depicts another embodiment of a sample electronic device including a composite structure; 
         FIG. 10B  depicts an exploded view of the sample electronic device of  FIG. 10A ; 
         FIG. 10C  depicts an enlarged view of the composite structure of  FIG. 10A ; and 
         FIG. 11  is a flow diagram of a method for manufacturing a device enclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The description that follows includes sample systems, methods, and apparatuses that embody various elements of the present disclosure. However, it should be understood that the described disclosure may be practiced in a variety of forms in addition to those described herein. 
     The present disclosure describes systems, devices, and techniques related to forming a device enclosure from dissimilar materials. The dissimilar materials may be affixed to one another to form a composite structure that may define multiple different features or elements of the device enclosure. For example, a first dissimilar material may form an enclosure component (e.g., including sidewalls, top and bottom panels, external cases, cover, or the like) and a second dissimilar material may form an internal component (e.g., including bosses, ribs, plates, shields, fasteners, or the like). Affixing the enclosure component and the internal component to form a composite structure may allow the device enclosure to exhibit material properties of one or both of the constituent dissimilar materials. 
     The enclosure component and the internal component may be non-separable within the composite structure. For example, the enclosure component and the internal component may be permanently affixed or coupled to one another such that the enclosure component and the internal component do not delaminate or separate without the composite structure breaking. In particular, the enclosure component and the internal component may be affixed to one another at or through a bonding region of the composite structure. The bonding region may include, or be defined by, a blended melt layer that is affixed to each of the enclosure component and the internal component. The blended melt region may be formed from an interstitial material and one or more of the dissimilar materials that form the enclosure component and the internal component. 
     A coupling process may affix the enclosure component to the internal component at the bonding region using the interstitial material. For example, the interstitial material may be adhered or affixed to one or both of the enclosure component and the internal component (e.g., platting, cladding, coatings, or the like, described herein) and have a melting temperature that is less than a melting temperature of either one of the enclosure component or the internal component. In this regard, in one embodiment, the coupling process may involve abutting the enclosure component and the internal component along a bonding region that includes the interstitial material, and subsequently heating the bonding region to a bonding temperature. The bonding temperature may be calibrated to melt the interstitial material and the one or more of the dissimilar materials that form the enclosure component and the internal component. This may cause the blended melt layer to form. In this regard, the blended melt layer may be defined by a heterogeneous layer having material elements of the interstitial material chemically or atomically bonded to material elements of the dissimilar materials. In other embodiments, as described herein, the coupling process may produce a blended melt layer substantially defined by the interstitial material (e.g., as may be the case when the coupling process causes the interstitial material to melt but not the aluminum component). 
     In an embodiment, the coupling process may affix the enclosure component and the internal component without melting the internal component at the bonding region. For example, the bonding temperature may be less than a melting temperature of the dissimilar material that forms the internal component. The interstitial material may be plated, cladded, or otherwise affixed to a surface of the internal component prior to forming the blended melt region. Accordingly, the internal component may be affixed to the blended melt region via the interstitial material. The interstitial material may thereby define a transition region at which a portion of the interstitial material is attached to the internal component (via plating, cladding, or the like) and another portion of the interstitial material is attached to the enclosure component (via the blended melt region). Where the dissimilar materials are, for example, aluminum and steel, this may result in composite structure with substantially reduced brittle intermetallic compounds that would impede or otherwise weaken the cohesiveness of an aluminum and steel bond. 
     It will be appreciated that the composite structure may include any appropriate interstitial material having material properties that allow it to affix to one, or both, of the dissimilar materials that form the blended melt region. As described herein, sample interstitial materials may include nickel, zinc, or aluminum components or alloy. In other embodiments, other interstitial materials are contemplated within the spirt of this disclosure. 
     The interstitial materials may be arranged in any appropriate shape, configuration, or position at the bonding region to facilitate the coupling process described herein. In one embodiment, the interstitial material may be deposited onto a surface of the enclosure component and the aluminum component prior to the coupling process. The coupling process may cause a portion of the interstitial material that is deposited on the enclosure component to melt with, and into, a portion of the interstitial material that is deposited on the internal component, thereby defining the blended melt layer of the composite structure. The respective interstitial materials may thus form direct or chemical bonds between one another, and optionally with one of the dissimilar materials, to form the blended melt layer that affixes the enclosure component and the internal component along the bonding region. 
     In another embodiment, the interstitial material may be deposited on the internal component prior to the coupling process and the enclosure component may be substantially free of interstitial material prior to the coupling process. The coupling process may cause a portion of the interstitial material to melt with a portion of the enclosure component to define the blended melt region of the composite structure through direct bonds between the enclosure component and the interstitial material. 
     A variety of techniques may be implemented to form the composite structure. In one non-limiting example, the enclosure component may be abutted to the internal component along a bonding region such that the interstitial material is positioned between the enclosure component and the internal component. The bonding region (or a portion thereof) may be heated to affix the enclosure component and the internal component in a manner that substantially reduces brittle intermetallic compounds, according to the embodiments described herein. For instance, heat may be applied to the bonding region to melt a portion of the interstitial material (and optionally a portion of one of the enclosure or internal components) without melting the other one of the enclosure or internal components. The bonding region may be heated by any appropriate technique, including direct heat (e.g., via a welding torch or similar implement), electrical heating elements, and/or other techniques operative to heat the bonding region, including techniques operative to heat a localized region of the bonding region. In some instances, a compression or ultrasonic vibration may be applied to the bonding interface to affix the enclosure and internal components. 
     The enclosure component and the internal components may be formed from a variety of dissimilar materials. In one embodiment, the enclosure component and the internal component may be formed from dissimilar metals, such as aluminum and steel. For example, the enclosure component may be an aluminum sheet that forms an exterior surface of a device enclosure and the internal component may be a steel component that defines a threaded feature (e.g., such as a threaded feature that receives a threaded fastener for securing a printed circuit board (PCB) to the enclosure component). The blended melt region may affix the aluminum component and the steel component. For example, as described herein, the blended melt region may include an interstitial material and a portion of the aluminum component, such that the blended melt region is formed by direct bonds between the interstitial material and the aluminum component. This may substantially reduce brittle intermetallic compounds that may otherwise be present when directly bonding aluminum to steel. Further, the blended melt region may allow the steel component to be affixed to an anodized or otherwise coated or treated aluminum structure. In other embodiments, other dissimilar metals are contemplated. 
     In other embodiments, one of the dissimilar materials may be a ceramic. For example, the enclosure component may be a ceramic sheet that forms an exterior surface of a device enclosure and the internal component may be a steel component that defines a threaded feature, as described above. The blended melt region may affix the ceramic component and the steel component. For example, as described herein, the blended melt region may include an interstitial material and a portion of the aluminum component, such that the blended melt region is formed by direct bonds between the interstitial material and one or both of the ceramic component or the steel component. In a particular implementation, the interstitial material may extend between the ceramic and metal components and may be a foil or a sheet constructed from tin, aluminum, or other material having a lower melting point than that of the metal component (e.g., such as a lower melting temperature than a titanium component). A bonding tool, such as an ultrasonic transducer or other appropriate tool, may press the metal component toward the interstitial material and ceramic component and cause the metal component to rotate. The linear and/or rotational movement between the components may cause the interstitial material to melt, but not the metal or ceramic components. This may result in a molecular bond between the mating materials. 
     Reference will now be made to the accompanying drawings, which assist in illustrating various features of the present disclosure. The following description is presented for purposes of illustration and description. Furthermore, the description is not intended to limit the inventive aspects to the forms disclosed herein. Consequently, variations and modifications commensurate with the following teachings, and skill and knowledge of the relevant art, are within the scope of the present inventive aspects. 
       FIG. 1  depicts an example electronic device  104  having an composite structure, such as the composite structure generally discussed above and described in more detail below. For purposes of illustration, the electronic device  104  is depicted as having an enclosure  108 , a display  112  (e.g., including a touch-sensitive display configured to receive input), one or more input/output members  116 , and a speaker  120 . It should be noted that the electronic device  104  may also include various other components, such as one or more ports (e.g., charging ports, data transfer ports, or the like), additional input/output buttons, and so on. As such, the discussion of any electronic device, such as electronic device  104 , is meant as illustrative only. 
     The electronic device  104  may be substantially any type of device having an enclosure formed from dissimilar materials. Some example electronic devices may include desktop computers, notebook computers, smart phones (as shown in  FIG. 1A ), tablets, portable media players, or the like. Other example electronic devices may include wearable devices (including watches, gloves, rings, or the like), health monitoring devices (including pedometers, heart rate monitors, or the like), and other electronic devices, including digital cameras, printers, scanners, security systems or devices. In some cases, the electronic device  104  need not be an electronic device. For example, the electronic device  104  may be substantially any device with an outer shell, housing, enclosure, or the like constructed from dissimilar materials that form a composite structure having an interstitial material. 
     In one embodiment, the enclosure  108  may be formed from a composite structure having an enclosure component and an internal component affixed to one another using an interstitial materials that form a blended melt layer. This may allow the enclosure  108  to have dissimilar materials affixed to one another and forming different features or elements of the enclosure  108 . For example, the enclosure  108  may include an enclosure component formed from an enclosure material and an internal component formed from a metal material different than the enclosure material affixed to one another along a bonding region defined by the blended melt layer (not shown in  FIG. 1 ). As described in greater detail below, the enclosure component may define an exterior surface  150  of the enclosure  108  and enclose or define an internal volume of the electronic device  104 . The internal component may be affixed to the enclosure component within the internal volume and may be a structural component of the electronic device. 
     In one embodiment, the enclosure  108  may be constructed of various combinations of aluminum and steel components. In one embodiment, the enclosure  108  may include an enclosure component formed from an aluminum or aluminum alloy and the internal component may be a steel component of steel alloy. The aluminum alloy may provide a durable, chemical resistant barrier between internal components of the electronic device (e.g., the PCB, sensors, switches or the like) and an external environment. For example, the enclosure  108  may be exposed to an external environment containing various contaminants, including oils, sweat, dust, moisture, and/or other contaminants that may adversely affect the operation of the electronic device  104 . The aluminum component may physically obstruct such contaminants from entering the enclosure  108 . Further, the aluminum component may exhibit a chemical resistivity such that it does not substantially break down, degrade, corrode, or otherwise diminish when exposed to the contaminants. The steel or steel alloy that forms the internal component may be bonded to the aluminum component within the internal volume of the electronic device and provide enhanced rigidity and hardness to the exterior surface  150  that is defined by the aluminum component. Additionally, the steel or steel alloy may be machineable, for example, to define a threaded feature or other structural member that is used to connect a component of the electronic device (e.g., such as the PCB) to the enclosure  108 . In some cases, the internal component may be configured to electrically conduct a signal received from the PCB. 
     It will be appreciated that the foregoing example constructions of the enclosure  108  are presented for purposes of illustration. Other embodiments of the enclosure  108  formed from a composite structure of aluminum and steel are contemplated within the scope of this disclosure. For example, in some cases, the enclosure component may be formed from steel and the internal component may be formed from aluminum. Additionally or alternatively, the enclosure  108  may include a steel component having aluminum components affixed to opposing surfaces of the steel component using an interstitial material formed along each of the opposing surfaces of the steel component. In other cases, the enclosure  108  may include an aluminum component having steel components affixed to opposing surfaces of the aluminum component using an interstitial material formed along each of the opposing surface of the aluminum component. In other embodiments, other constructions of the enclosure  108  are completed, including embodiments having multiple, alternating layers of aluminum components affixed to steel components, according to the embodiments described herein. 
     In another implementation, the enclosure  108  may include a composite structure formed from a ceramic and a metal material. For example, the enclosure  108  may include an enclosure component formed from a ceramic material and an internal component formed from a metal material. The ceramic material and the metal material may be affixed to one another along a bonding region defined by an interstitial material (not shown in  FIG. 1 ). As one possibility, as described with respect to  FIG. 7 , the internal components may be metal embossments or other protrusions affixed to the ceramic enclosure component outer surface using a bonding tool that rotates the metal component such that the interstitial material melts and subsequently bonds the metal and ceramic components to one another. In some cases, the metal component may be a decorative or aesthetic enhancement to the ceramic component. In other cases, the metal component may be a structural component of the electronic device  104  (e.g., such as an attachment feature configured to structurally support electronic circuitry of the electronic device  104 ). 
       FIG. 2  is a cross-sectional view of the electronic device  104  of  FIG. 1 , taken along line A-A of  FIG. 1 . As illustrated, the electronic device  104  includes the enclosure  108  and device components  124 . The device components  124  may be a PCB, sensor, or any other internal component of the electronic device  104 . For example, one or more of the device components  124  may be a PCB that is configured to control a function of the electronic device  104 . The PCB may include contacts (not shown) for conducting electrical signals and/or detecting an actuation of a switch. 
     The enclosure  108  may be constructed from a set of layers. As shown in  FIG. 2 , the enclosure  108  includes an internal component  128 , an interstitial material  132 , and an enclosure component  136 . The enclosure component  136  is shown proximal to the exterior surface  150  of the enclosure  108  and the internal component  128  is shown proximal to, or at, an interior volume defined by the enclosure  108 . As shown in  FIG. 2 , the enclosure  108  may optionally include an exterior layer  140 . The exterior layer  140  may be a cover glass formed from sapphire, conundrum, silica, or the like that may define the exterior surface  150 . In some cases, as described with respect to  FIG. 3 , the exterior layer  140  may extend over the enclosure component  136  and the display  112 . Additionally or alternatively, the exterior layer  140  may be defined partially or fully by a coating, paint, ink or other material that may provide a protective seal, decorative trim, or the like disposed on, or over, enclosure component  136 . 
     In an embodiment, the enclosure component  136  may be constructed entirely, or partially, from aluminum or various aluminum alloys (e.g., including aluminum-based compounds having one or more of silicon, iron, copper, manganese, magnesium, or other appropriate elements). In some cases, the aluminum may be an anodized aluminum structure. The enclosure component  136  may be shaped in any appropriate manner for a given application, including linear and non-linear shapes. In some instances, the enclosure component  136  may be substantially planar and may resemble a plate or a sheet structure. The aluminum of the enclosure component  136  may have a melting temperature that is less than a melting temperature of the internal component  128  (e.g., where the internal component  128  is formed from steel or steel alloy). In some cases, the aluminum of the enclosure component  136  may have a melting temperature within a range of 800 degrees Fahrenheit to 1300 degrees Fahrenheit, based on the material composition of the aluminum. In other embodiments, the aluminum of the enclosure component  136  may have a melting temperature that is less than 800 degrees Fahrenheit or greater than 1300 degrees Fahrenheit. 
     The internal component  128  may be constructed entirely, or partially, from steel or various steel alloys (e.g., including steel-based compounds having one or more of silicon, chromium, manganese, nickel, titanium, copper, or other appropriate elements). The internal component  128  may be shaped in any appropriate manner for a given application, including linear and non-linear shapes. In some instances, the internal component  128  may be substantially planar and may resemble a plate or a sheet structure. In other cases, as described with respect to  FIGS. 8A-10C , the internal component  128  may define a threaded feature, boss, plate, shield, rib, or other feature of the enclosure  108 . In this regard, the internal component  128  may be a structural component of the enclosure  108  that is configured to secure a component of the electronic device  104 , such as a PCB, to the enclosure component  136 . In some cases, the internal component  128  may be configured to electrically conduct a signal received from the PCB. 
     The steel of the internal component  128  may have a melting temperature that is greater than the melting temperature of the enclosure component  136  (e.g., where the enclosure component  136  is formed from aluminum or aluminum alloy). In some cases, the steel of the internal component  128  may have a melting temperature within a range of 2600 degrees Fahrenheit to 2800 degrees Fahrenheit, based on the material composition of the steel. In other embodiments, the steel of the internal component  128  may have a melting temperature that is less than 2600 degrees Fahrenheit or greater than 2800 degrees Fahrenheit. 
     The interstitial material  132  may be positioned between the internal component  128  and the enclosure component  136 . The interstitial material  132  may be used to define or form a blended melt layer between the internal component  128  and the enclosure component  136 . In this manner, the internal component  128  and the enclosure component  136  may be affixed to one another via the interstitial material  132 . As described in greater detail below (e.g., as described with respect to  FIGS. 4A-4C ), in one embodiment, a portion of the interstitial material  132  may be directly or chemically bonded with a portion of the internal component  128  at the blended melt layer (e.g., a region of the enclosure  108  at which heat is applied to melt the interstitial material  132 , and optionally the enclosure component  136 , without melting the internal component  128 ). 
       FIG. 3  is a cross-sectional view of the electronic device  104  of  FIG. 1 , taken along line B-B of  FIG. 1 . As illustrated, the electronic device  104  includes enclosure  108 ′ and the display  112 . The enclosure  108 ′ shown and described with respect to  FIG. 3  may be substantially analogous to the enclosure  108  described with respect to  FIG. 2 . For example, the enclosure  108 ′ may include the enclosure component  136 ; the interstitial material  132 ; the internal component  128 ; and the exterior layer  140 . 
     Notwithstanding the foregoing similarities to the enclosure  108 , the enclosure  108 ′ may be configured such that both the enclosure component  136  and the internal component  128  are positioned proximal to the exterior surface  150  of the enclosure  108 . As shown in  FIG. 3 , the internal component  128  may form a portion of the enclosure  108 ′ and may be separated from the display  112  by an opening  114 . The opening  114  may be formed by the enclosure  108  and configured to receive the display  112 . This may facilitate attachment of the display  112  to the device components  124 . The exterior layer  140  may be a cover glass or other transparent, or partially transparent, layer that defines at least a portion of the exterior surface  150 . In this regard, the exterior layer  140  may extend over the enclosure component  136 , the interstitial material  132 , the internal component  128 , the opening  114 , and the display  112 . Accordingly, the exterior layer  140  may form a cosmetic layer and/or a function component of the electronic device  104 , such as by forming a transparent and protective layer over the display  112 . 
       FIG. 4A  illustrates a first component  404  and a second component  412  prior to affixing the first component  404  and the second component  412  to create a composite structure. The first component  404  is shown as having a first interstitial material  408 . The second component  412  is shown as having a second interstitial material  416 . The first component  404  and the second component  412  may be substantially analogous to the enclosure component  136  and the internal component  128 , respectively, described above with respect to  FIGS. 1-3 . However, it will be appreciated that the first and second components  404 ,  412  may be substantially components of the electronic device  104  described above, including embodiments in which the first and second components  404 ,  412  are substantially analogous to the internal component  128  and the enclosure component  136 , respectively. 
     In one embodiment, the first and second interstitial materials  408 ,  416  may be constructed entirely, or partially, from nickel or various nickel alloys (e.g., including nickel-based compounds having one or more of chromium, cobalt, iron, titanium, tungsten, molybdenum, or other appropriate elements). Additionally or alternatively, the first and second interstitial materials  408 ,  416  may be constructed entirely, or partially, from zinc (e.g., Zn), or various zinc alloys (e.g., including zinc-based compounds having one or more of copper, nickel, silver, aluminum, magnesium, lead, or other appropriate elements). In other embodiments, the first and second interstitial materials  408 ,  416  may be constructed from one or more aluminum alloys. 
     The first and second interstitial materials  408 ,  416  may have a melting temperature that is less than a melting temperature of the second component  412 . For example, where the first and second interstitial materials  408 ,  416  are constructed from nickel, the first and second interstitial materials  408 ,  416  may have a melting temperature substantially within a range of 1600 degrees Fahrenheit to 2700 degrees Fahrenheit. In other cases, where the first and second interstitial materials  408 ,  416  are constructed from zinc, the first and second interstitial materials  408 ,  416  may have a melting temperature substantially within a range of 750 degrees Fahrenheit to 1750 degrees Fahrenheit. The first and second interstitial materials  408 ,  416  need not be constructed from the same materials. For instance, the first and second interstitial materials  408 ,  416  may be constructed from different alloys. Accordingly, the first and second interstitial materials  408 ,  416  may have different melting temperatures, as may be appropriate for a given application. 
     The first interstitial material  408  may be affixed to the first component  404 . In one embodiment, the first interstitial material  408  may be plated, cladded, and/or coated onto a surface of the first component  404 . In other embodiments, other techniques for affixing the first interstitial material  408  to the first component  404  are contemplated within the scope of the present disclosure. The first interstitial material  408  is affixed to the first component  404  prior to the affixing of the first component  404  and the second component  412  to create a composite structure. The combination of the first component  404  and the first interstitial material  408  may therefore define a non-separable structure that is affixed to the second component  412  within the composite structure. 
     The second interstitial material  416  may be affixed to the second component  412 . In one embodiment, the second interstitial material  416  may be plated, cladded, and/or coated onto a surface of the second component  412 . In other embodiments, other techniques for affixing the second interstitial material  416  to the second component  412  are contemplated within the scope of the present disclosure. The second interstitial material  416  is affixed to the second component  412  prior to the affixing of the first component  404  to the second component  412  to create a composite structure. The combination of the second component  412  and the second interstitial material  416  may therefore define a non-separable structure that is affixed to the first component  404  within the composite structure. 
       FIG. 4B  shows the first component  404  and the second component  412  combined to form a composite structure  450 . The composite structure  450  may be formed via a coupling process that affixes the first component  404  to the second component  412 , according to the embodiments described herein (e.g., as described with respect to  FIGS. 4C and 7 ). The composite structure  450  may include a blended melt layer  420 . As described with respect to  FIG. 4C , the blended melt layer  420  may be formed from a portion of one or more of the material of the first component  404  and the first and second interstitial materials  408 ,  416 . The blended melt layer  420  may be positioned between the first component  404  and the second component  412 . The blended melt layer  420  may be affixed to both the first component  404  and the second component  412 . In this regard, the first component  404  may be affixed to the second component  412  via the blended melt layer  420 . 
       FIG. 4C  depicts detail  1 - 1  of  FIG. 4B  of the composite structure  450 . As shown in the non-limiting example of  FIG. 4C , the blended melt layer  420  may include a diminished interstitial material  424  and a transition layer  428 . The diminished interstitial material  424  and the transition layer  428  may be at least partially formed from (with reference to  FIG. 4A ) the interstitial materials  408 ,  416  as a result of the coupling processes described herein. 
     In one embodiment, a coupling process may involve positioning the first component  404  and the second component  412  such that the interstitial materials  408 ,  416  abut. The coupling process may heat the first component  404 , the second component  412 , and the first and second interstitial materials  408 ,  416  (or portions or combinations thereof) to a bonding temperature that melts a portion of the material that forms the first component  404  and a portion of one, or both, of the first and second interstitial materials  408 ,  416 . Melting the portion of the first component  404  and the portion of one, or both, of the first and second interstitial materials  408 ,  416  may form the transition layer  428 . As such, the transition layer  428  may include a region of the composite structure  450  at which portions of the first component  404  are directly or chemically bonded to the elements of the first or second interstitial materials  408 ,  416 . The diminished interstitial material  424  may be formed from the portion of one, or both, of the first and second interstitial materials  408 ,  416 , for example, that may not be melted or otherwise formed into the transition layer  428 . The diminished interstitial material  424  may not include material from the second component  412 ; as the second component is not melted, the diminished interstitial material  424  may remain affixed to the second component  412 , but not melted or blended together. 
     The coupling process may cause the first component  404  to affix to the transition layer  428 . For example, the coupling process may melt the first component  404  at or near the surface of the first component  404  where the first interstitial material  408  is positioned. The melted portion of the first component  404  may therefore melt into, and form with, one or both of the first and second interstitial materials  408 ,  416  to form the composite structure  450 . The portion of the first component  404  not melted as a result of the coupling process may therefore be affixed with the transition layer  428  upon the cooling of the composite structure  450 . The first component  404  depicted in  FIG. 4C  thus may be smaller than, or diminished from, the first component  404  depicted in  FIG. 4A . 
     In a similar manner, the coupling process may cause the diminished interstitial material  424  to be affixed with the transition layer  428 . As one example, a portion of the second interstitial material  416  may be melted into, and formed with, the transition layer  428 . The portion of the second interstitial material  416  not melted as result of the coupling process may therefore be affixed with the transition layer  428  upon the cooling of the composite structure  450 . The diminished interstitial material  424  deposited in  FIG. 4C  may therefore be smaller than, or diminished from, the second interstitial material  416  depicted in  FIG. 4A . 
     It will be appreciated that, in some embodiments, the blended melt layer  420  need not include the diminished interstitial material  424 . For example, the blended melt layer  420  may be substantially defined by the transition layer  428 . This may occur where substantially all of the first and second interstitial materials  408 ,  416  are melted as a result of the coupling process. 
     Alternatively, the blended melt layer  420  need not include the transition layer  428 . For example, the blended melt layer  420  may be substantially defined by the diminished interstitial material  424 . This may occur where the first component  404  is not melted as a result of the coupling process. For example, rather than melt the first component  404 , the coupling process may melt a portion of each of the first and second interstitial materials  408 ,  416  to define the blended melt layer  420 . Stated differently, the first interstitial material  408  may be directly or chemically bonded to the second interstitial material  416 , thereby affixing the first component  404  to the second component  412  without melting the first component  404  or the second component  412 . 
     As illustrated in  FIG. 4C , the diminished interstitial material  424  is affixed to the second component  412 . The interface between the diminished interstitial material  424  and the second component  412  may be substantially the same as the interface between the second interstitial material  416  and the second component  412  depicted in  FIG. 4A . In this manner, the diminished interstitial material  424  may be affixed to the second component  412  within the composite structure  450  via a plating, cladding, or other appropriate bonding technique. The coupling process may not melt the second component  412  (e.g., the bonding temperature utilized in the coupling process may be less than a melting temperature of the second component  412 ). Accordingly, the second component  412  may be substantially the same size and shape as the second component  412  depicted in  FIG. 4A . 
       FIG. 5A  illustrates a first component  504  and a second component  512  prior to affixing the first component  504  and the second component  512  to create a composite structure. The first component  504  is shown as positioned adjacent a first interstitial sheet  508 . The second component  512  is shown positioned adjacent a second interstitial sheet  516 . The first component  504  and the second component  512  may be substantially analogous to the enclosure component  136  and the internal component  128 , respectively, described above with respect to  FIGS. 1-3 . However, it will be appreciated that the first and second components  504 ,  512  may be substantially components of the electronic device  104  described above, including embodiments in which the first and second components  504 ,  512  are substantially analogous to the internal component  128  and the enclosure component  136 , respectively. 
     The first and second interstitial sheets  508 ,  516  may be substantially analogous to the first and second interstitial materials  408 ,  416  described above with respect to  FIGS. 4A-4C . For example, the first and second interstitial sheets  508 ,  516  may be formed from various metallic elements, including nickel, zinc, and aluminum alloy and have a melting temperature that is less than a melting temperature of the second component  512 . Notwithstanding the foregoing, the first and second interstitial sheets  508 ,  516  may be a film, laminate, sheet, and/or other conforming or substantially planar layer that may be applied to one or both of the first and second components  504 ,  512 . In some cases, the first and second interstitial sheets  508 ,  516  may be used to augment or otherwise tailor a volume of interstitial material used to form a composite structure from the first and second components  504 ,  512 . Additionally or alternatively, the first and second interstitial sheets  508 ,  516  may be configured to conform to (and at least partially fill) irregularities or other surface imperfections within the first and second components  504 ,  512  that may otherwise impede bonding. 
       FIG. 5B  shows the first component  504  and the second component  512  combined to form a composite structure  550 . The composite structure  550  may be formed via a coupling process that affixes the first component  504  to the second component  512 , according to the embodiments described herein (e.g., as described with respect to  FIGS. 4C and 7 ). The composite structure  550  may include a blended melt layer  520 . The blended melt layer  520  may be positioned between the first component  504  and the second component  512 . The blended melt layer  520  may be attached to both the first component  504  and the second component  512 . In this regard, the first component  504  may be affixed to the second component  512  via the blended melt layer  520 . 
     The composite structure  550  may be constructed in a manner substantially analogous to the composite structure  450  depicted in  FIGS. 4A-4C . For example, the composite structure  550  may be constructed using the coupling process described with respect to  FIG. 4C . Notwithstanding the foregoing similarities, the blended melt layer  520  may be at least partially defined by one or more of the first and second interstitial sheets  508 ,  516 . To illustrate, the coupling process may involve positioning the first component  504  and the second component  512  such that the first and second interstitial sheets  508 ,  516  abut. The coupling process may heat the first component  504 , the second component  512 , and the first and second interstitial sheets  508 ,  516  (or portions or combinations thereof) to a bonding temperature. This may cause a portion of the first component  504  and a portion of one, or both, of the first and second interstitial sheets  508 ,  516  to melt. Melting the portion of the first component  504  and the portion of one, or both, of the first and second interstitial sheets  508 ,  516  may partially form the blended melt layer  520 . This may allow the first component  504  and the first and second interstitial sheets  508 ,  516  to be affixed to one another via direct or chemical bonding. The bonding temperature may be less than a melting temperature of the second component  512 . In this regard, the second component  512  may be affixed to the blended melt layer  520  (and thus to the first component  504 ), rather than being partially melted into the blended melt layer  520 . 
       FIG. 6A  illustrates a first component  604  and a second component  612  prior to affixing the first component  604  and the second component  612  to create a composite structure. The second component  612  is shown as having a interstitial material  616 . The first component  604  and the second component  612  may be substantially analogous to the enclosure component  136  and the internal component  128 , respectively, described above with respect to  FIGS. 1-3 . However, it will be appreciated that the first and second components  604 ,  612  may be substantially components of the electronic device  104  described above, including embodiments in which the first and second components  604 ,  612  are substantially analogous to the internal component  128  and the enclosure component  136 , respectively. 
     The interstitial material  616  may be affixed to the second component  612  in the same manner as (with reference to  FIG. 4A ) the second interstitial material  416  is affixed to the second component  412 . For example, the interstitial material  616  may be plated, cladded, coated or otherwise affixed to the second component  612 . 
       FIG. 6B  shows the first component  604  and the second component  612  combined to form a composite structure  650 . The composite structure  650  may be formed via a coupling process that affixes the first component  604  to the second component  612 , according to the embodiments described herein (e.g., as described with respect to  FIGS. 4C and 7 ). The composite structure  650  may include a blended melt layer  620 . The blended melt layer  620  may be positioned between the first component  604  and the second component  612 . The blended melt layer  620  may be attached to both the first component  604  and the second component  612 . In this regard, the first component  604  may be affixed to the second component  612  via the blended melt layer  620 . 
     The composite structure  650  may be constructed in a manner substantially analogous to the composite structure  450  depicted in  FIGS. 4A-4C . For example, the composite structure  650  may be constructed using the coupling process described with respect to  FIG. 4C . Notwithstanding the foregoing similarities, the blended melt layer  620  may be at least partially defined by the interstitial material  616 . To illustrate, the coupling process may involve positioning the first component  604  and the second component  612  such that the interstitial material  616  and the first component  604  abut. The coupling process may heat the first component  604 , the second component  612 , and the interstitial material  616  (or portions or combinations thereof) to a bonding temperature. This may cause a portion of the first component  604  and a portion of the interstitial material  616  to melt. Melting the portion of the first component  604  and the portion of the interstitial material  616  may partially form the blended melt layer  620 . This may allow the first component  604  and the interstitial material  616  to be affixed to one another via direct or chemical bonding. The bonding temperature may be less than a melting temperature of the second component  612 . In this regard, the second component  612  may be affixed to the blended melt layer  620  (and thus to the first component  604 ), rather than being partially melted into the blended melt layer  620 . 
     In an embodiment, various ultrasonic bonding techniques may be used to affix two dissimilar materials via an interstitial material. For example, a bonding tool, ultrasonic transducer, or appropriate tool may induce rotational and/or axial movement in at least one of the dissimilar materials that causes the interstitial material to melt, and establish a molecular bond between the dissimilar materials. 
     In this regard,  FIG. 7  depicts a bonding operation that may be used to form a composite structure of dissimilar materials using an ultrasonic bonding tool. As illustrated, the bonding operation includes a bonding tool  702 . The bonding tool  702  may be an ultrasonic transducer or other rotary tool designed for high speed rotational movement and may be capable of performing a rotational interstitial welding operation. For example, the bonding tool  702  may rotate or oscillate in a generally circular direction about a longitudinal direction of the bonding tool  702  while compressing one or more materials positioned along the longitudinal axis. The bonding tool  702  may rotate or oscillate according to a predetermined frequency that is configured to heat a bonding region between the dissimilar materials. Sample frequencies for the operation of the bonding tool  702  include 15 kHz, 20 kHz, 30 kHz, 35 kHz, 40 kHz, and 70 kHz; however, it will be appreciated that other frequencies are contemplated. 
     The bonding tool  702  may be releasably coupled with an internal component  704 . For example, the internal component  704  may be temporarily affixed to the bonding tool  702  during axial and/or rotational movement of the bonding tool  702 , and subsequently disengaged (e.g., after cessation of the axial and/or rotational movement). In this regard, as shown in  FIG. 7 , a portion of the internal component  704  may be received by the bonding tool  702 . This engagement of the internal component  704  and the bonding tool  702  may therefore cause the internal component  704  to rotate and/or translate in response to corresponding rotational or axial movements of the bonding tool  702 . In an embodiment, the internal component  704  may be any appropriate metal structure, as described herein, including being constructed from titanium, steel, or other metal or metal alloys. In other cases, the internal component  704  may be constructed from other materials. 
     The bonding tool  702  may press the internal component  704  to abut an interstitial material  720 . The interstitial material  720  may be a foil or a sheet constructed from tin, aluminum or other material having a lower melting point than that of the internal component  704 , including zinc and nickel, as described herein. The interstitial material  720  may have a thickness that is substantially less than the thickness of the internal component  704 . 
     The interstitial material  720  may be positioned on an exterior surface of an enclosure component  712 . The enclosure component  712  may be any appropriate ceramic component, including being constructed from zirconia aluminum (ZrO 2 AI 2 O 3 ), zirconia (ZrO 2 ), or other ceramic-based material. In other cases, the enclosure component  712  may be an aluminum or aluminum alloy structure. For some cases, the enclosure component  712  may form an outer casing or shell of an electronic device housing, such as for the electronic device  104  described with respect to  FIGS. 1-3 . In an embodiment, the enclosure component  712  may be constructed from a ceramic or ceramic-based material. 
     In operation, the bonding tool  702  may move the internal component  704  towards the enclosure component  712  so as to compress the interstitial material  720  between the internal component  704  and the enclosure component  712 . Subsequently, the bonding tool  702  may cause the internal component  704  to rotate relative to the interstitial material  720  and enclosure component  712  while maintaining the compression of the interstitial material  720  between the internal component  704  and the enclosure component  712 . The rotation of the internal component  704  by the bonding tool  702  may generate heat within the interstitial material  720  and surrounding portions of the internal component  704  and the enclosure component  712 . This may cause a portion of the interstitial material  720  to melt and form a molecular bond with one or both of the internal component  704  and/or the enclosure component  712 . 
     The bonding tool  702  may continue to translate and rotate the internal component  704  until a sufficient bond strength is reached that causes the internal component  704  and the enclosure component  712  to permanently affix to one another. Upon completion of the bonding, the bonding tool  702  may be disengaged from the internal component  704 . 
       FIGS. 8A-10C  depict various electronic devices having composite structures. Broadly, the composite structures described above with respect to  FIGS. 1-7  may be used to form various components of an electronic device. For example, the composite structures may be used to form a portion of an enclosure, housing, or other feature of an electronic device. In some cases, as described in greater detail below, the composite structures may include an enclosure component that forms a wall or surface of a device enclosure and an internal component that forms a structural member of the enclosure (e.g., a threaded connection, a structural rib, and so on). The enclosure component and the internal component may be affixed to one another, as described herein, such that the structural member may be bonded with the wall or surface of the enclosure. 
       FIG. 8A  depicts an example electronic device  804 . The electronic device  804  may include, or be formed from, a composite structure, such as the composite structures  450 ,  550 ,  650  described above with respect to  FIGS. 4A-6B . As shown in  FIG. 8A , the electronic device  804  may be a portable electronic device, such as a mobile phone, tablet computer, or other computing device having a touch-sensitive display positioned within an enclosure or housing. In other embodiments, as described herein, the electronic device  804  may be substantially any type of electronic device having an enclosure component affixed to an internal component via an interstitial material. 
     For purposes of illustration, electronic device  804  is shown having an enclosure  808 , a display  812 , one or more input/output members  816 , and a speaker  820 . It should be noted that the electronic device  804  may also include various other components, such as one or more ports (e.g., charging ports, data transfer ports, or the like), additional input/output buttons, and so on. As such, the discussion of any electronic device, such as electronic device  804 , is meant as illustrative only. 
     The enclosure  808  may be formed from various combinations of composite structures, for example, such as from various combinations of enclosure and internal components affixed to one another using an interstitial material. In one embodiment, one or more walls of the enclosure  808  may be substantially formed from an enclosure component formed from an enclosure material that defines or encloses an internal volume. An internal component (not shown in  FIG. 8A ) formed from a metal material that is different than the enclosure material may be affixed to the enclosure component within the interior volume via an interstitial material, thereby forming a composite structure. 
       FIG. 8B  depicts an exploded view of an embodiment of the electronic device  804  shown in  FIG. 8A . In the exploded view, for purposes of illustration, the enclosure  808  is shown separated into a top portion and a bottom portion. However, it will be appreciated that the enclosure  808  may be a substantially integrally formed or unitary structure or, alternatively, may include multiple separable pieces that collectively define the enclosure  808 . 
     As described above, the enclosure  808  may be formed partially or fully from an enclosure component and an internal component that form a composite structure. For example, the enclosure  808  may include an interior surface  850  formed from an enclosure material. Internal components may be affixed to the enclosure component along the interior surface  850 . For example, as shown in  FIG. 8B , threaded features  854  may be affixed to the interior surface  850 . The threaded features  854  affixed to the interior surface  850  may form a composite structure, as described herein. For example, the threaded features  854  may be an internal component of the enclosure  808  and substantially formed from a metal material that is affixed (via an interstitial material) to the enclosure material that forms the interior surface  850 . The threaded features  854  may be mounting features, bosses, or other structural members that are used to connect or secure one or more components of the electronic device  804  to the enclosure  808 . 
     In this regard, as shown in  FIG. 8B , the electronic device  804  may include a printed circuit board (PCB)  890 . The PCB  890  may include electrical components  892  (e.g., processing units, switches, sensors, wires, or the like) that control one or more functions of the electronic device  804 . The PCB  890  may be secured to the interior surface  850  of the enclosure  808  using the threaded features  854 . For example, the PCB  890  may define openings  894 . The threaded features  854  may be advanced through respective ones of the openings  894  such that the PCB  890  is secured to enclosure  808 . 
       FIG. 8C  depicts detail  2 - 2  of  FIG. 8B  of the interior surface  850 . As shown in the non-limiting example of  FIG. 8C , one of the threaded features  854  is affixed to the interior surface  850 . The threaded features  854  shown in  FIG. 8B  may be affixed to the interior surface  850  via an interstitial materials  858 . The interstitial material  858  may define a bonding region that affixes the threaded features  854  and the interior surface  850 . For example, the interstitial material  858  may include a plated, cladded, or coated interstitial material (e.g., including zinc, nickel, aluminum alloy, or the like) that bonds the metal material of the threaded feature  854  to the enclosure material of the interior surface  850  as a result of a coupling process. The coupling process may involve melting a portion of the metal material and the interstitial material and/or applying a localized compression force to the internal and enclosure components. It will be appreciated that the interstitial material  858  may have a thickness that is substantially less than a thickness of the enclosure  808  or the threaded feature  854 , and is therefore depicted in  FIG. 8C  for purposes of illustration only. 
       FIG. 9A  depicts an example electronic device  904 . The electronic device  904  may include, or be formed from, a composite structure, such as the composite structures  450 ,  550 ,  650  described above with respect to  FIGS. 4A-6B . As shown in  FIG. 9A , the electronic device  904  may be a laptop computer. In other embodiments, as described herein, the electronic device  904  may be substantially any type of electronic device having an enclosure component affixed to an internal component via an interstitial material. 
     For purposes of illustration, electronic device  904  is shown having an enclosure  908 , a display  912 , one or more input/output members  916 , and a keyboard assembly  920 . It should be noted that the electronic device  904  may also include various other components, such as one or more ports (e.g., charging ports, data transfer ports, or the like), additional input/output buttons, and so on. As such, the discussion of any electronic device, such as electronic device  904 , is meant as illustrative only. 
     The enclosure  908  may be formed from various combinations of composite structures, for example, such as from various combinations of enclosure and internal components affixed to one another using an interstitial material. In one embodiment, one or more walls of the enclosure  908  may be substantially formed from an enclosure component formed from an enclosure material that defines or encloses an internal volume. An internal component (not shown in  FIG. 9A ) formed from a metal material that is different than the enclosure material may be affixed to the enclosure component within the interior volume via an interstitial material, thereby forming a composite structure. 
       FIG. 9B  depicts an exploded view of an embodiment of the electronic device  904  shown in  FIG. 9A . In the exploded view, for purposes of illustration, the enclosure  908  is shown separated into a top portion and a bottom portion. However, it will be appreciated that the enclosure  908  may be a substantially integrally formed or unitary structure or, alternatively, may include multiple separable pieces that collectively define the enclosure  908 . 
     As described above, the enclosure  908  may be formed partially or fully from an enclosure component and an internal component that form a composite structure. For example, the enclosure  908  may include an interior surface  950  formed from an enclosure material. Various internal components may be affixed to the enclosure component along the interior surface  950   
     As one example, shown in  FIG. 9B , threaded features  954  may be affixed to the interior surface  950 . The threaded features  954  affixed to the interior surface  950  may form a composite structure, as described herein. For example, the threaded features  954  may be an internal component of the enclosure  908  and substantially formed from a metal material that is affixed (via an interstitial material) to the enclosure material that forms the interior surface  950 . The threaded features  954  may be mounting features, bosses, or the like that are used to connect or secure one or more components of the electronic device  904  to the enclosure  908 . 
     In this regard, as shown in  FIG. 9B , the electronic device  904  may include a printed circuit board (PCB)  990 . The PCB  990  may include electrical components  992  (e.g., processing units, switches, sensors, wires, or the like) that control one or more functions of the electronic device  904 . The PCB  990  may be secured to the interior surface  950  of the enclosure  908  using the threaded features  954 . For example, the PCB  990  may define openings  994 . The threaded features  954  may be advanced through respective ones of the openings  994  such that the PCB  990  is secured to enclosure  908 . 
     The electronic device  904  may include various other composite structures. As shown in  FIG. 9B , the electronic device  904  may include an internal component that defines ribs  970  that are affixed to the interior surface  950 . The ribs  970  affixed to the interior surface  950  may form a composite structure, as described herein. For example, the ribs  970  may be an internal component of the enclosure  908  and substantially formed from a metal material that is affixed (via an interstitial material) to the enclosure material that forms the interior surface  950 . The ribs  970  may be structural ribs that enhance or provide rigidity to the enclosure  908 , such as providing rigidity to an exterior surface of the enclosure  908 . 
     The ribs  970  may extend across the interior surface  950  in multiple directions. For example, the ribs  970  may extend between sidewalls of the enclosure  908 . In some cases, the ribs  970  separate an internal volume of the enclosure  908  into discrete compartments. These discrete compartments may be used to secure and/or separate various electronic components or other features of the electronic device  904 , for example, such as the PCB  990 . In this regard, as described in greater detail below with respect to  FIG. 9D , the ribs  970  may define a passage that allows a set of wires  980  to extend between the discrete compartments of the internal volume of the enclosure  908 . 
     As another example, as shown in  FIG. 9B , the electronic device  904  may include an internal component that defines pins  960 . The pins  960  affixed to the interior surface  950  may form a composite structure, as described herein. For example, the pins  960  may be substantially formed from a metal material that is affixed (via an interstitial material) to the enclosure material that forms the interior surface  950 . The pins  960  may be structural members of the electronic device  904  that may, for example, connect the top and bottom portion of the enclosure  908 . 
     As another example, as shown in  FIG. 9B , the electronic device  904  may include an internal component that defines a shield  982 . The shield  982  may be an electrically or thermally conductive element that shields or protects one or more components of the electronic device  904  from undesirable interference. For example, the shield  982  may be shield or protect one or more components of the electronic device  904  form electromagnetic radiation. The shield  982  affixed to the interior surface  950  may form a composite structure, as described herein. For example, the shield  982  may be substantially formed from a metal material that is affixed (via an interstitial material) to the enclosure material that forms the interior surface  950 . 
       FIG. 9C  depicts detail  3 - 3  of  FIG. 9B  of the interior surface  950 . As shown in the non-limiting example of  FIG. 9C , one of the threaded features  954  is affixed to the interior surface  950 . The threaded features  954  shown in  FIG. 9C  may be affixed to the interior surface  950  via an interstitial material  958 . The interstitial material  958  may define a bonding region that affixes the threaded feature  954  and the interior surface  950 . For example, the interstitial material  958  may include a plated, cladded, or coated interstitial material (e.g., including zinc, nickel, aluminum alloy, or the like) that bonds the metal material of the threaded feature  954  to the enclosure material of the interior surface  950  as a result of a coupling process. The coupling process may involve melting a portion of the enclosure material and the interstitial material  958  and/or applying a localized compression force to the internal and enclosure components. It will be appreciated that the interstitial material  958  may have a thickness that is substantially less than a thickness of the enclosure  908  or the threaded feature  954 , and is therefore depicted in  FIG. 9C  for purposes of illustration only. 
       FIG. 9D  depicts detail  4 - 4  of  FIG. 9B  of the interior surface  950 . As shown in the non-limiting example of  FIG. 9D , one of the ribs  970  is affixed to the interior surface  950 . The ribs  970  shown in  FIG. 9D  may be affixed to the interior surface  950  via an interstitial material  958 . As described above, the interstitial material  958  may define a bonding region that affixes the ribs  970  and the interior surface  950 . For example, the interstitial material  958  may include a plated, cladded, or coated interstitial material (e.g., including zinc, nickel, aluminum alloy, or the like) that bonds the metal material of the ribs  970  to the enclosure material of the interior surface  950  as a result of a coupling process. The coupling process may involve melting a portion of the metal material and the interstitial material and/or applying a localized compression force to the internal and enclosure components. It will be appreciated that the interstitial material  958  may have a thickness that is substantially less than a thickness of the enclosure  908  or the ribs  970 , and is therefore depicted in  FIG. 9D  for purposes of illustration only. 
     As described above, the ribs  970  may separate an internal volume of the enclosure  908  into discrete compartments. The discrete compartments may house or contain various electrical components, including PCB  990 . In this regard, as shown in  FIG. 9D , the ribs  970  may define a passage  972 . The passage  972  may be a through portion or opening formed into a localized region of the ribs  970 . The passage  972  may be configured to allow the set of wires  980  to extend between the discrete compartments of the internal volume of the enclosure  908 . This may allow the ribs  970  to enhance the structural integrity of the enclosure  908  while facilitating electrical connections between the various electrical components of the electronic device  904 . 
       FIG. 10A  depicts an electronic device  1004 . The electronic device  1004  may include, or be formed from, a composite structure, such as the composite structures  450 ,  550 ,  650  described above with respect to  FIGS. 4A-6B . As shown in  FIG. 10A , the electronic device  1004  may be a portable electronic device, such as a watch, or other computing device having a touch-sensitive display positioned within an enclosure or housing. In other embodiments, as described herein, the electronic device  1004  may be substantially any type of electronic device having an enclosure component affixed to an internal component via an interstitial material. 
     For purposes of illustration, the electronic device  1004  is shown having an enclosure  1008 , a display  1012 , one or more input/output members  1016 , and a speaker band  1024 . It should be noted that the electronic device  1004  may also include various other components, such as one or more ports (e.g., charging ports, data transfer ports, or the like), additional input/output buttons, and so on. As such, the discussion of any electronic device, such as electronic device  1004 , is meant as illustrative only. 
     The enclosure  1008  may be formed from various combinations of composite structures, for example, such as from various combinations of enclosure and internal components affixed to one another using an interstitial material. In one embodiment, one or more walls of the enclosure  1008  may be substantially formed from an enclosure component formed from an enclosure material that defines or encloses an internal volume. An internal component (not shown in  FIG. 10A ) formed from a metal material that is different than the enclosure material may be affixed to the enclosure component within the interior volume via an interstitial material, thereby forming a composite structure.  FIG. 10B  depicts an exploded view of an embodiment of the electronic device  1004  shown in  FIG. 10A . In the exploded view, for purposes of illustration, the enclosure  1008  is shown separated into a top portion and a bottom portion. However, it will be appreciated that the enclosure  1008  may be a substantially integrally formed or unitary structure or, alternatively, may include multiple separable pieces that collectively define the enclosure  1008 . 
     As described above, the enclosure  1008  may be formed partially or fully from an enclosure component and an internal component. For example, the enclosure  1008  may include an interior surface  1050  formed from an enclosure material. Internal components may be affixed to the enclosure component along the interior surface  1050 . For example, as shown in  FIG. 10B , threaded features  1054  may be affixed to the interior surface  1050 . The threaded feature  1054  affixed to the interior surface  1050  may form a composite structure, as described herein. For example, the threaded features  1054  may be an internal component of the enclosure  1008  and substantially formed from a metal material that is affixed (via an interstitial material) to the enclosure material that forms the interior surface. The threaded features  1054  may be mounting features, bosses, or other structural members that are used to connect or secure one or more components of the electronic device  1004  to the enclosure  1008 . 
     In this regard, as shown in  FIG. 10B , the electronic device  1004  may include a printed circuit board (PCB)  1090 . The PCB  1090  may include electrical components  1092  (e.g., processing units, switches, sensors, wires, or the like) that control one or more functions of the electronic device  1004 . The PCB  1090  may be secured to the interior surface  1050  of the enclosure  1008  using the threaded features  1054 . For example, the PCB  1090  may define openings  1094 . The threaded feature  1054  may be advanced through respective ones of the openings  1094  such that the PCB  1090  is secured to enclosure  1008 . 
       FIG. 10C  depicts detail  5 - 5  of  FIG. 10B  of the interior surface  1050 . As shown in the non-limiting example of  FIG. 10C , one of the threaded features  1054  is affixed to the interior surface  1050 . The threaded feature  1054  shown in  FIG. 10B  may be affixed to the interior surface  1050  via an interstitial material  1058 . The interstitial material  1058  may define a bonding region that affixes the threaded feature  1054  and the interior surface  1050 . For example, the interstitial material  1058  may include a plated, cladded, or coated interstitial material (e.g., including zinc, nickel, aluminum alloy, or the like) that bonds the metal material of the threaded feature  1054  to the enclosure material of the interior surface  1050  as a result of a coupling process. The coupling process may involve melting a portion of the enclosure material and the interstitial material and/or applying a localized compression force to the internal and enclosure components. It will be appreciated that the interstitial material  1058  may have a thickness that is substantially less than a thickness of the enclosure  1008  or the threaded feature  1054 , and is therefore depicted in  FIG. 10C  for purposes of illustration only. 
     To facilitate the reader&#39;s understanding of the various functionalities of the embodiments discussed herein, reference is now made to the flow diagram in  FIG. 11 , which illustrates process  1100 . While specific steps (and orders of steps) of the methods presented herein have been illustrated and will be discussed, other methods (including more, fewer, or different steps than those illustrated) consistent with the teachings presented herein are also envisioned and encompassed with the present disclosure. 
     With reference to  FIG. 11 , process  1100  relates generally to a method of manufacturing a device enclosure having a composite structure, such as the composite structures described herein. The “coupling process” described as forming the various composite structures (e.g., composite structures,  450 ,  550 ,  650 ) may be accomplished using the process  1100 . 
     At operation  1104 , an enclosure component may abut an internal component along a bonding region. For example and with reference to  FIGS. 4A-4C , the first component  404  may abut the second component  412  at a bonding region substantially defined by the blended melt layer  420 . At least the second component  412  may include a interstitial material (e.g., second interstitial material  416 ). In some cases, the first component  404  may also include a interstitial material (e.g., first interstitial material  408 ). Accordingly, operation  1104  may cause the second interstitial material  416  to contact the first component  404  or the second component  412 . 
     At operation  1108 , the enclosure component may affix to the internal component by heating a bonding region to a temperature that is less than a melting temperature of one of the enclosure component or the internal component. For example and with reference to  FIGS. 4A-4C , subsequent to the abutment of the first component  404  and the second component  412 , the first component  404 , the second component  412 , and one, or both, of the first and second interstitial materials  408 ,  416  (or portions or combination thereof) may be heated to a bonding temperature. This may cause, for example, a portion of the first component  404  and a portion of one or both of the first and second interstitial materials  408 ,  416  to melt without melting the second component  412 . 
     Operation  1108  may occur subsequent to anodizing at least of the internal component or the enclosure component. For example, the enclosure component may be anodized aluminum structure that is affixed, via process  1100  to a steel internal component. In this regard, according to the embodiments described herein, the steel internal component may be affixed to an anodized enclosure component. This may be due, in part, to the blended melt layer  420  formed as a result of process  1100  that affixes the internal component and the enclosure component to one another. 
     In some cases, the internal component may be used to affix an electronic component of the electronic device to the enclosure component. For example, with reference to  FIG. 8B , the second component  812  may be, or otherwise form, the threaded feature  854 . In this regard, the PCB  890  depicted in  FIG. 8B  may be attached to the first component  404  (that may define the interior surface  850 ) by advancing a pin through the PCB  890  and into the threaded feature  854 . 
     The melted portion of the first component  404  and the portion of the one, or both, of the first and second interstitial materials  408 ,  416  may form a blended melt layer positioned between the first component  404  and the second component  412 . The blended melt layer may be a heterogeneous layer at which the first component  404  is directly or chemically bonded to one, or both, of the first and second interstitial materials  408 ,  416 . The second component  412  may be affixed to the blended melt layer either directly or via a portion of the second interstitial material  416  that does not melt as a result of the operation  1108 . 
     Various techniques may be implemented to heat the bonding region to the bonding temperature, including techniques to heat a localized region of the bonding region. In some circumstances, the bonding region may be heated by direct heat (e.g., a welding torch or similar implement) and/or an electrical heating element. In other instances, a generalized or localized compression force may be applied to the first component  404  and the second component  412 . The compression force may be used to bond the first component  404  and the second component  412  at the blended melt layer  420 . Additionally or alternatively, an ultrasonic vibration may be applied to the first component  404  and the second component  412 . The ultrasonic vibration may be used to bond the first component  404  and the second component  412  at the blended melt layer  420 . In some cases, it may be desirable to actively cool or quench the bonding region, for example, to mitigate material defects at the blended melt layer  420  caused by phase changes within the blended melt layer  420 . 
     In some embodiments, a surface treatment may be performed on a surface of the first component  404 , the second component  412 , and/or the blended melt layer  420 . The surface treatment may include polishing, buffing, sand blasting, or coating (or other appropriate treatments) an outer surface of one or more of the first component  404 , the second component  412 , and/or the blended melt layer  420 . In some cases, the first component  404 , the second component  412 , and/or the blended melt layer  420  may form an outer surface of an electronic device (e.g., such as the electronic device depicted in  FIG. 1 ). In this regard, the surface treatment may be performed on an outer surface of the electronic device, which may protect and/or aesthetically enhance the outer surface of the electronic device. For example, the outer surface of the electronic device may be coated so that there is no visible seam between the first component  404  and the second component  412 . 
     Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Further, the term “exemplary” does not mean that the described example is preferred or better than other examples. 
     The foregoing description, for purposes of explanation, uses specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20190912
Publication Date: 20220816
Grant Date: 20220816
Priority Date: 20160921
Inventors: MISRA, ABHIJEET
OSBORNE, STEVEN J.
SPRAGGS, IAN A.
RAMMAH, MARWAN
COUNTS, WILLIAM A.
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/163", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0283", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0249", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0283", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0249", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/185", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/163", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/185", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04M1/185", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/163", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/026", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0249", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0283", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 61617725