PATENT DOCUMENT

Publication Number: US-11784673-B2
Application Number: US-202117469001-A
Country: US
Kind Code: B2

Title: Electronic device housing having a radio-frequency transmissive component

Abstract:
An electronic device component including a thermoset composite material is described herein. The electronic device component may be a structural component of the housing and define an exterior surface of the housing. The electronic device component may also be transparent to radio-frequency signals.

Claims:
What is claimed is: 
     
       1. An electronic device comprising:
 a radio-frequency (RF) component; and 
 an enclosure defining an internal cavity and at least partially surrounding the RF component, the enclosure comprising:
 a housing formed from a metal material and defining:
 a first exterior surface of the enclosure; 
 a first surface extending inward from a first portion of the first exterior surface, 
 a second surface facing the first surface and extending inward from a second portion of the first exterior surface; and 
 a retention feature extending into the internal cavity; and 
 
 a window formed from an RF-transmissive material, positioned over the RF component, adhered to the first and the second surfaces, and engaged with the retention feature, the RF-transmissive material defining a second exterior surface of the enclosure and including a thermoset composite material comprising nano-sized silica particles dispersed within a thermoset matrix. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein the thermoset composite material has:
 a hardness from 70 to 95 on a Shore D hardness scale; and 
 an impact strength from 50 J/m to 90 J/m. 
 
     
     
       3. The electronic device of  claim 1 , wherein the thermoset composite material has a dielectric constant from 2 to 4 as measured at a frequency of 2.5 GHz. 
     
     
       4. The electronic device of  claim 1 , wherein:
 the first and the second portions of the first exterior surface and the second exterior surface together define a curved region of the enclosure. 
 
     
     
       5. The electronic device of  claim 1 , wherein the RF component is part of a wireless communication system. 
     
     
       6. The electronic device of  claim 1 , wherein the RF component is a wireless receiver component of a wireless charging system. 
     
     
       7. The electronic device of  claim 1 , wherein:
 the thermoset composite material is a first thermoset composite material; 
 the thermoset matrix is a first thermoset matrix; and 
 the window further comprises a second thermoset composite material comprising fibers dispersed within a second thermoset matrix and defining a portion of an interior surface of the enclosure. 
 
     
     
       8. An electronic device comprising:
 an enclosure comprising:
 a housing component formed from a metal material and defining:
 a first exterior surface of the enclosure; 
 an opening extending from the first exterior surface of the enclosure to an interior surface of the housing component; and 
 a retention feature positioned along the interior surface of the housing component; and 
 
 a dielectric component positioned within the opening, adhered to the housing component, and interlocked with the retention feature, the dielectric component defining a second exterior surface of the enclosure and including a thermoset composite material comprising an epoxy matrix and nano-sized silica particles dispersed within the epoxy matrix; and 
 
 a RF component positioned within the enclosure and below the dielectric component. 
 
     
     
       9. The electronic device of  claim 8 , wherein:
 the electronic device further comprises wireless transmission circuitry; 
 the RF component is an antenna operably coupled to the wireless transmission circuitry; and 
 the dielectric component defines an RF-transmissive window for the antenna. 
 
     
     
       10. The electronic device of  claim 8 , wherein:
 the thermoset composite material has an ultimate tensile strength from 30 MPa to 50 MPa and an elongation from 10% to 15%. 
 
     
     
       11. The electronic device of  claim 8 , wherein:
 the opening of the housing component is partially defined by:
 a first surface extending from a first portion of the first exterior surface of the enclosure to a first portion of the interior surface of the housing component; and 
 a second surface facing the first surface and extending from a second portion of the first exterior surface of the enclosure to a second portion of the interior surface of the housing component; and 
 
 the dielectric component is adhered to each of the first and the second surfaces. 
 
     
     
       12. The electronic device of  claim 11 , wherein:
 the retention feature is a first retention feature; and 
 the housing component further defines a second retention feature along the first surface and a third retention feature along the second surface. 
 
     
     
       13. The electronic device of  claim 11 , further comprising:
 a first anodization layer along the first surface and defining a first set of nano-sized pores; and 
 a second anodization layer along the second surface and defining a second set of nano-sized pores, the dielectric component extending at least partially into the first set of nano-sized pores and the second set of nano-sized pores. 
 
     
     
       14. The electronic device of  claim 13 , wherein:
 the housing component comprises a third anodization layer, different from the first anodization layer, along the first exterior surface of the enclosure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a nonprovisional application of and claims the benefit of U.S. Provisional Patent Application No. 63/079,419, filed Sep. 16, 2020 and titled “Electronic Device Housing Having a Radio-Frequency Transmissive Component,” the disclosure of which is hereby incorporated herein by reference its entirety. 
    
    
     FIELD 
     The described embodiments relate generally to components for electronic devices which include a thermoset composite material. More particularly, the present embodiments relate to housing or enclosure components that enable operation of wireless components of the electronic devices. 
     BACKGROUND 
     Some electronic devices may include wireless and/or RF-transmitting components that are configured to communicate or otherwise operably couple to other devices. Some electronic devices are formed from plastic housings or enclosures, which enable the transmission of various wireless signals. However, if an enclosure or housing is formed from a metal material, the conductive nature of the metal material may interfere with the signal transmission. 
     The systems and techniques described herein are directed to electronic devices that include a housing having an RF-transmissive component for facilitating wireless signal transmission. 
     SUMMARY 
     Embodiments described herein relate to components for electronic devices that include a thermoset composite material. The component including the thermoset composite material may be a component of the housing and may define an exterior surface of the housing. In some cases, the housing component is a structural component of the housing. 
     A housing component including a thermoset composite material may have a combination of properties which makes it suitable for use as a structural component of the housing. For example, such a housing component may be capable of being machined and polished but may still have sufficient strength and toughness to be scratch and impact resistant in use. In some cases, the housing component may resist brittle failure, substantial deformation, and/or separation from an adjoining housing component during a drop event. In addition, the housing component including the thermoset composite may be colorable to match a color of an adjoining housing component. 
     In some cases, the component including the thermoset composite material may form a transmissive window for an internal component of the device. For example, the component including the thermoset composite material may form a window for an emitter component, a receiver component, and/or a transceiver component positioned within the housing. In some cases, the component including the thermoset composite material may form a window for an antenna or a sensor. For example, the antenna may be operably coupled to wireless transmission circuitry of the electronic device. The component including the thermoset composite material may be transparent to radio-frequency signals. 
     The component including the thermoset composite material may be a dielectric component. In some cases, a radio-frequency (RF) transparent dielectric component forms a window for an RF transmitter, an RF receiver, and/or an RF transceiver. In additional cases, the dielectric component may provide electrical isolation between two electrically conductive housing components. 
     The thermoset composite material of the component typically includes a thermoset polymer which forms a cross-linked network. For example, the thermoset polymer may be an epoxy-based polymer or a polyurethane-based polymer. The thermoset composite material typically also includes nano-sized inorganic particles, such as silica particles. These nano-sized inorganic particles may be distributed in a matrix of the thermoset polymer. The thermoset composite material may also include additional components such as one or more pigments. 
     The disclosure herein also relates to electronic device housings and electronic devices including the components described herein. The electronic device typically includes device components positioned within the housing, such as a display, one or more sensors, and/or a battery. In some examples, the electronic device includes one or more components of a wireless communication system. 
     The disclosure provides an electronic device comprising a housing. The housing comprises a first housing component formed from a first metal material and defining a first portion of an exterior surface of the housing and a second housing component formed from a second metal material and defining a second portion of the exterior surface of the housing. The housing further comprises a dielectric component positioned between and bonded to the first and the second housing components, the dielectric component including a thermoset composite material comprising an epoxy matrix and nano-sized oxide particles dispersed within the epoxy matrix. 
     In addition, the disclosure provides an electronic device comprising a radio-frequency (RF) component and an enclosure at least partially surrounding the RF component. The enclosure comprises a housing formed from a metal material and defining an exterior surface, a first surface extending inward from a first portion of the exterior surface, and a second surface facing the first surface and extending inward from the second portion of the exterior surface. The enclosure further comprises a window formed from an RF-transmissive material, positioned over the RF component, and adhered to the first and the second surfaces, the RF-transmissive material including a thermoset composite material comprising nano-sized silica particles dispersed within a thermoset matrix. 
     The disclosure further provides a housing comprising a housing component formed from a metal material, having a textured wall, and defining a first portion of an exterior surface of the housing and a structural component bonded to the textured wall and defining a second portion of the exterior surface. The structural component is formed from a thermoset composite material comprising a cross-linked epoxy material and nano-sized oxide particles dispersed within the cross-linked epoxy material. 
    
    
     
       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 elements. 
         FIGS.  1 A and  1 B  show views of an example electronic device. 
         FIGS.  2 A,  2 B,  2 C, and  2 D  show examples of cross-sectional views of the device of  FIGS.  1 A- 1 B . 
         FIG.  3    shows another example of a cross-sectional view of the device of  FIGS.  1 A- 1 B . 
         FIG.  4    shows another example electronic device. 
         FIG.  5    shows an example cross-sectional view of the device of  FIG.  4   . 
         FIG.  6    shows another example cross-sectional view of the device of  FIG.  4   . 
         FIGS.  7 A and  7 B  show views of an additional example electronic device. 
         FIG.  8    shows an example cross-sectional view of the device of  FIGS.  7 A and  7 B . 
         FIG.  9    shows another example cross-sectional view of the device of  FIGS.  7 A and  7 B . 
         FIG.  10    shows another example electronic device. 
         FIG.  11    shows an example cross-sectional view of the device of  FIG.  10   . 
         FIG.  12    shows an example of a wearable electronic device. 
         FIG.  13    shows an example cross-sectional view of the device of  FIG.  12   . 
         FIGS.  14 A and  14 B  show an additional example of an electronic device. 
         FIGS.  15 A,  15 B , and  FIG.  15 C  show another example electronic device. 
         FIG.  16    shows a flow chart of an example process for forming a housing including a thermoset composite component. 
         FIGS.  17 A and  17 B  show examples of a housing assembly at different stages in the process of  FIG.  16   . 
         FIG.  18    shows a block diagram of a sample electronic device that can incorporate a component including a thermoset composite material. 
     
    
    
     The use of cross-hatching or shading in the accompanying figures is generally provided to clarify the boundaries between adjacent elements and also to facilitate legibility of the figures. Accordingly, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, element proportions, element dimensions, commonalities of similarly illustrated elements, or any other characteristic, attribute, or property for any element illustrated in the accompanying figures. 
     Additionally, it should be understood that the proportions and dimensions (either relative or absolute) of the various features and elements (and collections and groupings thereof) and the boundaries, separations, and positional relationships presented therebetween, are provided in the accompanying figures merely to facilitate an understanding of the various embodiments described herein and, accordingly, may not necessarily be presented or illustrated to scale, and are not intended to indicate any preference or requirement for an illustrated embodiment to the exclusion of embodiments described with reference thereto. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred implementation. To the contrary, the described embodiments are intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the disclosure and as defined by the appended claims. 
     The following disclosure relates to components for electronic devices, the components including a thermoset composite material. In some cases, a component including a thermoset composite material may be included in the housing of the electronic device. Such a housing component may have a combination of properties which makes it suitable for use as a structural component of the housing. For example, such a housing component may be capable of being machined and polished but may still have sufficient strength and toughness to be scratch and impact resistant in use. In some cases, the housing component may resist brittle failure, substantial deformation, and/or separation from an adjoining housing component during a drop event. In addition, the housing component including the thermoset composite may be colorable to match a color of an adjoining housing component. 
     In some cases, the housing of the electronic device also includes one or more housing components formed from a material other than the thermoset composite material. For example, the other housing component(s) may be formed from a metal, a glass, a glass-ceramic, a ceramic, or a combination of these materials. The housing component including the thermoset composite material may be bonded to one or more of these other housing components to provide structural integrity to the housing. In some embodiments, one or more housing components are formed from a metal material and a surface of the metal material is anodized to produce an anodization layer after the housing components are assembled with the component formed from the thermoset composite material. In some cases, the housing component including the thermoset composite material may be resistant to degradation and/or color change during processes such as an anodization or a physical vapor deposition process. 
     In additional cases, the component including the thermoset composite material may be positioned within an electronic device housing rather than serving as a housing component. In some examples, the thermoset composite material is part of an assembly positioned within the housing of the electronic device. When structural integrity of this interior assembly is important, the assembly component including a thermoset composite material can help provide structural support to the assembly. For example, the assembly may include a component formed from the thermoset composite material and one or more components formed from a metal. The component formed from the thermoset composite material may be bonded to the metal components to provide structural integrity to the assembly. In some cases, the component formed from the thermoset composite material may electrically isolate two or more components formed from a metal. The assembly may be positioned within a housing formed from one or more dielectric and/or low magnetic permeability materials. 
     The component including the thermoset composite material may be a dielectric component. In some cases, the dielectric properties of the component may allow sufficient transmission of radio waves that the component is considered to be transparent to radio frequencies. For example, the dielectric constant (relative permittivity) may be sufficiently low at a frequency range of interest to allow transmission of radio waves. The frequency range may be from a “low band” frequency range (e.g., less than 1 GHz, such as about 400 MHz to less than 1 GHz, about 600 MHz to about 900 MHz, or 600 MHz to 700 MHz), a “mid-band” frequency range (e.g., about 1 GHz to about 6 GHz, such as about 1 GHz to about 2.6 GHz, about 2 GHz to about 2.6 GHz, about 2.5 GHz to about 3.5 GHz, or about 3.5 GHz to about GHz), or a “high-band” frequency range (e.g., about 24 GHz to about 40 GHz, about 57 GHz to about 64 GHz, or about 64 GHz to about 71 GHz). In addition, wireless charging ranges may broadly be from about 80 kHz to about 300 kHz or from about 110 kHz to about 205 kHz. When the housing comprises electrically conducting components, a dielectric housing component may provide a window for an RF transmitter, an RF receiver and/or an RF transceiver. For example, the RF transmitter, RF receiver, and/or a RF transceiver may be part of a wireless communication system or a wireless charging system. 
     In additional cases, the dielectric component provides at least some extent of electrical isolation or insulation between two electrically conducting components. For example, a dielectric housing component may provide conductive and/or capacitive isolation between the two electrically conducting housing components. In some cases, at least one of the two electrically conducting housing components is configured to operate as an antenna. For example, at least one of the two electrically conducting housing components may be configured to radiate electromagnetic radiation for a wireless communication system. The dielectric housing component may electrically isolate this antenna from the other electrically conductive housing component. 
     In further cases, the component including the thermoset composite material may have properties suitable for allowing transmission of energy through electromagnetic induction. For example, the component including the thermoset composite material may form a window for an emitter, receiver, or transceiver for an inductive coupling wireless charging system. In some cases, the inductive coupling wireless charging system may be a resonant inductive coupling wireless charging system. The thermoset composite material may have a magnetic permeability sufficiently low that it does not interfere with transmission of magnetic fields generated by the inductive coupling wireless charging system. 
     A component predominantly composed of the thermoset composite material may be referred to herein as a thermoset composite component. A thermoset composite component may also be referred to as being formed from the thermoset composite material. In embodiments, the thermoset composite material includes a thermoset polymer, such as an epoxy-based polymer or a polyurethane-based polymer, which forms a cross-linked network. These examples of thermoset polymers may also be referred to herein as cross-linked epoxy materials and cross-linked polyurethane materials. The thermoset composite material typically also includes nano-sized inorganic particles, such as silica particles or other oxide particles. Including the nano-sized inorganic particles in the thermoset composite material can increase the strength and the toughness of the thermoset composite material as compared to thermoset polymer alone. The nano-sized inorganic particles may also affect the dielectric properties of the material. In some cases, the thermoset composite material further includes pigments which help to impart a durable color to the thermoset composite component. The description of thermoset composite materials provided with respect to  FIGS.  1 A,  1 B, and  16    is generally applicable here and, for brevity, is not repeated here. 
     In some cases, a structural housing component including a thermoset composite material has an ability to resist deformation without being overly brittle. The strength of a thermoset housing component may be indicated by one or more mechanical properties of the thermoset composite material, such as the hardness, the elastic modulus, or the fracture strength of the thermoset composite material. The ductility and the toughness of the thermoset composite component may be indicated by one or more additional mechanical properties of the thermoset composite material. For example, the ductility of the thermoset composite material may be indicated by the percent elongation or by the impact strength of the material. In some examples the mechanical property is measured at room temperature. The thermoset composite component may also be configured to have one or more thermal properties, such as a glass transition temperature, compatible with any manufacturing processes that occur after the thermoset composite is cured. The thermoset composite component may also have a shrinkage less than a threshold value. 
     As previously mentioned, the housing component including the thermoset composite material may be bonded to one or more adjacent components of the housing to provide structural integrity to the housing. In some cases, the bonding between the thermoset composite housing component and an adjacent housing component is enhanced by modifying a surface of the adjacent housing component. For example, the surface of the adjacent housing component can be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like. In further cases, a thermoset composite component may be structurally interlocked with larger scale retention features on the adjacent housing component. The bond strength between the thermoset composite material and the material of the adjoining housing component may be indicated by the lap shear strength between the thermoset composite material and the material of the adjoining housing component. 
     The disclosure herein also relates to electronic device housings and electronic devices including a component comprising a thermoset composite material. In some cases, the electronic device includes a wireless communication system. Wireless communication protocol and standards may include established protocols and standards such as IEEE 802.11x, GSM, LTE, CDMA, TDMA, 3G, 4G, 5G, Bluetooth, Bluetooth Low Energy (BLE), ISO/IEC 18000-3, Wi-Fi, Radio-frequency identification (RFID), Near-Field Communication (NFC), Global Positioning System (GPS), or any other target wireless communication protocol or standard (including yet-to-be-developed protocols and/or standards). As examples, the wireless communication may be a radio-frequency or an infrared communication system. The electronic device typically includes other components positioned within the device, such as a display, one or more sensors, and/or a battery. 
     These and other embodiments are discussed below with reference to  FIGS.  1 A to  18   . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIGS.  1 A and  1 B  show an example of an electronic device or simply “device”  100 . For purposes of this disclosure, the device  100  may be a portable electronic device including, for example a mobile phone, tablet computer, a portable computer, a wearable electronic device, a portable music player, a health monitoring device, a portable terminal, wireless charging device, device accessory, or other portable or mobile device. In the example of  FIGS.  1 A and  1 B , the dimensions and form factor, including the ratio of the length of its long sides to the length of its short sides, correspond to those of a mobile phone. However, this example is not limiting and examples of other device form factors are shown in  FIGS.  7 A,  7 B,  10 ,  12 ,  14 A,  15 A, and  15 B . 
     In the example of  FIGS.  1 A and  1 B , the device  100  includes a housing  110 , a front cover  122 , and a rear cover  124 . The housing  110  and the front and rear covers  122  and  124  enclose internal components of the electronic device and may be referred to collectively herein as an enclosure. In some cases, the device includes a support plate and/or additional internal structural components that are used to support internal electronic circuitry or electronic components. The example of  FIGS.  1 A and  1 B  is not limiting and in other examples internal components of the device may be enclosed by a housing lacking a cover, as shown in  FIGS.  14 A,  15 A, and  15 B , by a housing in combination with a single cover, as shown in  FIGS.  7 A and  7 B , or any other suitable configuration. 
     The housing  110  includes some housing components which include a thermoset composite material (e.g.,  114   b ). In some cases, these housing components are formed from the thermoset composite material and in other cases these housing components are formed from multiple composite materials (as shown in the example of  FIG.  9   ). The housing  110  also includes other housing components which are formed from a material other than the thermoset composite material (e.g.,  112   b  and  112   f ). As examples, each of these other housing components may be formed from a metal, a glass, a glass-ceramic, a ceramic, and combinations thereof. The number of housing components shown in  FIGS.  1 A and  1 B  is not limiting, and in other examples a housing may include a lesser or a greater number of housing components. 
     In some cases, a housing component formed from a thermoset composite material (e.g.,  114   b ) is coupled to one or more housing components formed from a material other than the thermoset composite material (e.g.,  112   b  and  112   f ). As explained in more detail with respect to  FIG.  16   , a housing component comprising the thermoset composite material may be formed by curing a polymerizable mixture. For example, the polymerizable mixture may be introduced into a gap between two or more of the other housing components and then cured. 
     In some embodiments, a surface of the housing component formed from the material other than the thermoset composite material can be modified to improve its bonding with the thermoset composite material. The surface modification may enhance interaction between the surface and the thermoset polymer and/or its pre-polymers. For example, the surface of the housing component can be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like. The description of surface modifications provided with respect to  FIGS.  2 B and  2 C  is generally applicable herein and, for brevity, is not repeated here. In addition, the housing component comprising the thermoset composite material may be structurally interlocked with larger scale features of the housing component formed from the material other than the thermoset composite material These features may be referred to herein as retention features or interlock features. A variety of retention features are described herein including, but not limited to, those illustrated with respect to  FIGS.  3 ,  5 - 6 ,  8 - 9 , and  14 B . 
     In some cases, the component including the thermoset composite material may provide a “window” for an internal device component configured to radiate (transmit) and/or receive electromagnetic signals. The thermoset composite material may be transmissive to wavelengths (or frequencies) of electromagnetic radiation transmitted and/or received by the internal device component. For example, the thermoset composite material may be an RF-transmissive material. In some cases, the thermoset composite material may be substantially transparent to one or more wavelengths (or frequencies) of the electromagnetic signal. For example, the thermoset composite material may transmit at least 50%, 60%, 70%, 80%, or 90% at a specified wavelength or frequency or over a specified range of wavelengths or frequencies. The internal device component may be an antenna and may be part of a wireless communication system. In some cases, the internal device component is configured to receive radio frequency (RF) signals. The frequency range may be from a “low band” frequency range (e.g., less than 1 GHz, such as about 400 MHz to less than 1 GHz, about 600 MHz to about 900 MHz, or 600 MHz to 700 MHz), a “mid-band” frequency range (e.g., about 1 GHz to about 6 GHz, such as about 1 GHz to about 2.6 GHz, about 2 GHz to about 2.6 GHz, about 2.5 GHz to about 3.5 GHz, or about 3.5 GHz to about GHz), or a “high-band” frequency range (e.g., about 24 GHz to about 40 GHz, about 57 GHz to about 64 GHz, or about 64 GHz to about 71 GHz). In addition, wireless charging ranges may broadly be from about 80 kHz to about 300 kHz or from about 110 kHz to about 205 kHz. 
     In some cases, the component including the thermoset composite material may be a dielectric component and dielectric properties of the component at a given frequency may be low enough that the component is substantially transparent to the electromagnetic signal. For example, the dielectric constant (relative permittivity) may be sufficiently low at a frequency range of interest to allow transmission of radio waves. In some cases, the thermoset composite material may have a dielectric constant (also referred to as the relative permittivity) of 2 to 4 or 2.5 to 3.5 at 2.5 GHz. The dissipation factor (also referred to as the loss tangent or tan delta) may be less than 0.5 or less than 0.4. In some cases, these parameters are measured per test method IEC-61189-2-721:2015. The component including the thermoset composite material, which may be a thermoset composite component, may have similar dielectric properties to the thermoset composite material. 
     In some cases, the dielectric component may provide at least some extent of electrical isolation between conducting housing components. For example, the dielectric strength may be sufficiently high to prevent or substantially limit electrical conduction through the dielectric component. Alternately or additionally, the dielectric strength may be sufficiently high to reduce capacitive coupling with an adjacent electrically conductive component. In some embodiments, at least one of these electrically conducting housing components is configured to operate as an antenna. For example, at least one of these conducting housing components may be configured to radiate electromagnetic radiation for a wireless communication system. The dielectric housing component may electrically isolate this antenna from an adjacent conducting housing component. In additional cases, the dielectric component may separate different regions of a conducting housing component, such as different regions surrounding an opening defined in the conducting housing component (e.g., an opening configured to operate as an emitter for a wireless communication system). 
     In some embodiments, the component may be predominantly made up of the thermoset composite material and may be referred to herein as a thermoset composite component. A thermoset composite component may also be referred to as being formed from the thermoset composite material. The thermoset composite material of the component includes a thermoset polymer, such as an epoxy-based polymer or a polyurethane-based polymer, which forms a crosslinked network. The thermoset composite material typically also includes inorganic particles, such as nano-sized inorganic particles. The inclusion of nano-sized inorganic particles in the thermoset composite material can increase the strength and the toughness of the thermoset composite material as compared to thermoset polymer alone. In addition, the inclusion of inorganic particles in the thermoset composite material can affect the dielectric constant of the thermoset composite material. The additional description of epoxy-based and polyurethane-based polymers provided with respect to  FIG.  16    is generally applicable herein and, for brevity, is not repeated here. 
     The thermoset polymer typically forms a matrix for a reinforcement material. This matrix may also be referred to herein as a thermoset matrix. For example, the matrix may be an epoxy-based matrix, which may also be referred to as an epoxy matrix herein. The reinforcement material may be substantially dispersed within the matrix of the thermoset polymer. In some cases, the reinforcement material may be in the form of particles. For example, the particles may include nano-sized oxide particles (e.g., having a size from 1 nm to 100 nm). In some embodiments, the thermoset composite material includes nano-sized silica particles. Nano-sized ceramic particles, such as zirconia, alumina, and/or titanium dioxide particles may alternately or additionally be included the thermoset composite material. However, ceramics having a greater dielectric constant than silica may be less suitable when a substantially RF-transparent component is desired. The nano-sized oxide particles may be substantially non-magnetic. The loading of the nano-sized silica or ceramic particles may be from about 10 wt % to about 50 wt %. In additional embodiments, at least some of the particles may have a larger size, such as greater than 100 nm and less than 20 microns (micrometers). The additional description of nano-sized and larger sized silica and ceramic particles provided with respect to  FIG.  16    is generally applicable herein and, for brevity, is not repeated here. 
     In some cases, the thermoset composite material includes one or more pigments which help to impart a durable color to the thermoset composite component. In some cases, the particles of the pigment may be micro-sized or nano-sized. As examples, the pigment may be an inorganic pigment, a carbon pigment, an organic pigment, or combinations thereof. The additional description of pigments provided with respect to  FIG.  16    is generally applicable herein and, for brevity, is not repeated here. 
     In some embodiments, the component including the thermoset composite material is a structural component of the housing. A structural housing component including a thermoset composite material may have an ability to resist deformation without being overly brittle. The strength of a thermoset housing component may be indicated by one or more mechanical properties of the thermoset composite material, such as the hardness, the elastic modulus, or the fracture strength of the thermoset composite material. For example, the thermoset composite material may have a hardness from 60 to 100 or from 70 to 95 on the Shore D hardness scale. As an additional example, the thermoset composite material may have a fracture strength (ultimate tensile strength UTS) of from 30 MPa to 50 MPa or from 30 MPa to 40 MPa. In some cases, the tensile strength is measured per ASTM D638 with Type IV dogbone sample. 
     The ductility and the toughness of the thermoset composite component may be indicated by one or more additional mechanical properties of the thermoset composite material. For example, the ductility of the thermoset composite material may be indicated by the percent elongation or by the impact strength of the material. In some cases, the percent elongation of the material is from 10% to 15%. The impact strength may be measured using a notched-bar impact test, such as an Izod impact test. In some cases, the impact strength of the thermoset composite material is from 40 J/m to 90 J/m or from 50 J/m to 90 J/m as measured by an Izod impact test. In some cases, the impact strength is measured with per ASTM D256. In some examples, the mechanical property is measured at room temperature. In some cases, a mechanical property may be measured directly on the thermoset composite component while in other cases the mechanical property may be measured on a sample of the thermoset composite material cured to about the same degree of crosslinking. 
     The thermoset composite component may also be configured to have one or more other properties. For example, a structural housing component may have a glass transition temperature of 60° C. to 90° C., 65° C. to 85° C., or 70° C. to 80° C. The thermoset composite component may also have a shrinkage less than 8% or less than 5%. In some cases, these other properties may be measured directly on the thermoset composite component while in other cases the property may be measured on a sample of the thermoset composite material cured to about the same degree of crosslinking. 
     As previously mentioned, a housing component including a thermoset composite material may be bonded to one or more other housing components to provide structural integrity to the housing. In some embodiments, the bonding between these components includes adhesive bonding. In some cases, the bonding between the thermoset composite material and the material of the adjoining housing component is indicated by the lap shear strength between the thermoset composite material and the material of the adjoining housing component. In some cases, the lap shear strength is greater than 20 MPa or greater than 25 MPa as measured using a single lap test. In some cases, the lap shear strength is greater than 20 MPa and up to 50 MPa or greater than 25 MPa and up to 50 MPa. In some cases, the lap shear strength may be measured per ASTM D1002. In some cases, the bonding may be measured directly on the thermoset composite component while in other cases the mechanical property may be measured on a sample of the thermoset composite material cured to about the same degree of crosslinking. 
     The housing  110  of  FIGS.  1 A and  1 B  includes multiple housing components ( 112   a  through  112   f  and  114   a  through  114   f ), each of the housing components defining a respective portion of an exterior surface of the housing. In addition, the housing  110  defines a side surface  106  of the electronic device. The housing component  114   f  is located between the housing components  112   c  and  112   d  and is not visible in the views of  FIGS.  1 A and  1 B . 
     In the example of  FIGS.  1 A and  1 B , the housing  110  includes six housing components including the thermoset composite material. In some cases, each of these six housing components is a dielectric housing component. In the example of  FIGS.  1 A and  1 B , each of the housing components  114   a ,  114   b ,  114   c ,  114   d ,  114   e , and  114   f  include a thermoset composite material. In some cases, one or more of the housing components  114   a  through  114   f  are formed from a thermoset composite material (and are predominantly made up of the thermoset composite material). In some cases, each of the housing components  114   a  through  114   f  is formed from substantially the same thermoset composite material. In other cases, one or more of the housing components  114   a  through  114   f  are formed from thermoset composite material including reinforcing particles in combination with thermoset composite material including the fibers as shown and described with respect to  FIG.  9   . The description provided with respect to  FIG.  9    is generally applicable herein and is not repeated here. 
     The housing  110  also includes six housing components formed from a material other than the thermoset composite material. In  FIGS.  1 A and  1 B , each of the housing components  112   a ,  112   b ,  112   c ,  112   d ,  112   e , and  112   f  are formed from a material other than the thermoset composite material. As examples, each of the housing components  112   a  through  112   f  may be formed from a metal, a glass, a glass-ceramic, a ceramic, and the like. In some cases, one or more of the housing components  112   a  through  112   f  is electrically conductive (also simply referred to as conductive). By the way of example, a housing component formed from a metal (also referred to as a metal material) may be formed from an aluminum alloy, steel, a titanium alloy, a magnesium alloy, or similar materials. A housing component formed from a glass and/or a glass ceramic (also referred to as a glass and/or glass ceramic material) may be formed from an aluminosilicate glass and/or glass ceramic. A housing component formed from a ceramic (also referred to as a ceramic material) may be formed from alumina (e.g., polycrystalline alumina or sapphire), zirconia, another metal oxide, a metal carbide, a metal boride, a metal nitride, a metal silicide, and the like. In some cases, each of the housing components  112   a  through  112   f  is formed from substantially the same material. As referred to herein, a housing component formed from a particular material, such as a metal, may also include a relatively thin coating of a different material along one or more surfaces, such as an anodization layer, a physical vapor deposited coating, a paint coating, a primer coating (which may include a coupling agent), or the like. In some cases, one or more openings may be formed in the housing  110 , such as the openings  135  and  136  formed in the component  112   b . As examples, such an opening may be provided over a speaker or a microphone, may surround a button or other type of input device, or may allow access to a charging port. 
     In some cases, a housing component including a thermoset composite material partially or completely fills a gap between adjacent two housing components formed from a material other than the thermoset composite material. For example, the housing component  114   b  may partially or completely fill a gap between the adjacent housing components  112   b  and  112   f . In some cases, the housing component including a thermoset composite material (e.g.,  114   b ) mechanically or structurally couples two adjacent housing components (e.g.,  112   b  and  112   f ). 
     In some embodiments, the housing  110  includes multiple electrically conductive housing components and multiple dielectric housing components which include the thermoset composite material. For example, the housing components  112   a  through  112   f  may be formed from a metal material (e.g., a metal alloy) and the housing components  114   a  through  114   f  may be formed of the thermoset composite material. In some cases, at least one of the housing components formed from the electrically conductive material is configured to operate as an antenna. For example, at least one of the two electrically conducting housing components may be configured to radiate electromagnetic radiation for a wireless communication system. The dielectric housing component including the thermoset composite material may electrically isolate this antenna from an adjacent electrically conducting housing component. 
     The front cover  122  may be positioned over a display  142  and may provide a window through which the display may be viewed. In some cases, the display  142  is a touch-sensitive display. The display  142  may be a liquid-crystal display (LCD), a light-emitting diode (LED) display, an LED-backlit LCD display, an organic light-emitting diode (OLED) display, an active layer organic light-emitting diode (AMOLED) display, and the like. In some embodiments, the display  142  may be attached to (or abut) the front cover  122 . The front cover  122  may at least partially define a front surface  102  of the electronic device. An opening  134  may be provided in the front cover  122  and in some cases may provide a speaker port. The device  100  may also include a front-facing camera  132 . 
     The exterior surface of the rear cover  124  may at least partially define a rear surface  104  of the electronic device. In the example of  FIG.  1 B , the rear cover may include a thicker region  144  which accommodates one or more optical modules  156  of a camera assembly. The thicker region  144  may be integrally formed with the surrounding portion of the rear cover or may be provided by a separate cover piece which is coupled to the surrounding portion of the rear cover (e.g., by a coupling ring). 
     The electronic device  100  further includes a camera assembly which in turn includes the one or more optical modules  156 . The camera assembly may define any number of optical modules such as one, two, three, four, five, or six optical modules. The optical modules may include, but are not limited to, a camera module, an illumination module, a sensor, and combinations thereof. When the camera assembly includes multiple camera modules, each of the camera modules may have a different field of view or other optical property. In some cases, a camera module includes an optical sensor array and/or an optical component such as a lens, filter, or window. In additional cases, a camera module includes an optical sensor array, an optical component, and a camera module housing surrounding the optical sensor array and the optical components. The camera module may also include a focusing assembly. For example, a focusing assembly may include an actuator for moving a lens of the camera module. In some cases, the optical sensor array may be a complementary metal-oxide semiconductor (CMOS) array or the like. In some cases, the camera assembly may include one or more sensors such as a depth measuring sensor (e.g., a time of flight sensor), an ambient light sensor, an infrared sensor, an ultraviolet light sensor, a health monitoring sensor, a biometric sensor (e.g., a fingerprint sensor) or the like. 
     Typical covers described herein are thin, and typically include a cover member that is less than 5 mm in thickness, and more typically less than 3 mm in thickness, less than or equal to 2 mm in thickness, or less than or equal to 1 mm in thickness. The front cover  122  and the rear cover  124  may be coupled to the housing  110 . For example, each of the front cover  122  and the rear cover  124  may be coupled to the housing with an adhesive, a fastener, an engagement feature, or a combination thereof. 
     Each of the front cover  122  and the rear cover  124  typically includes a cover member which may be a glass member, a glass ceramic member, or a member comprising one or more glass portions and one or more glass ceramic portions. The cover member may be chemically strengthened by ion exchange. In some cases, a cover may include multiple layers, each layer selected from a glass layer, a glass ceramic layer, and a polymer layer. A cover such as the front cover  122  and the rear cover  124  may further include one or more coatings. For example, the cover may include an exterior coating such as an oleophobic coating and/or an anti-reflective coating. Alternately or additionally, the cover may also include an interior coating such as a masking layer. 
     In addition to a display and a camera assembly, the electronic device  100  may include additional components. These additional components may comprise one or more of a processing unit, control circuitry, memory, an input/output device, a power source (e.g., battery), a charging assembly (e.g., a wireless charging assembly), a network communication interface, an accessory, and a sensor. Components of a sample electronic device are discussed in more detail below with respect to  FIG.  18    and the description provided with respect to  FIG.  18    is generally applicable herein. 
       FIG.  2 A  shows an example of a partial cross-sectional view of an electronic device  200 . In particular,  FIG.  2 A  shows an example of a housing  210 . The housing  210  includes a housing component  214   b  including a thermoset composite material. The housing component  214   b  is positioned between two housing components  212   b ,  212   f  which are formed from a material other than the thermoset composite material. The cross-section through the housing  210  may be an example of a lateral cross-section through the housing  110  along A-A in  FIG.  1 A . The housing components  212   b ,  212   f , and  214   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b ,  112   f , and  114   b  respectively and, for brevity, that description is not repeated here. 
     In the example of  FIG.  2 A , the housing component  214   b  including the thermoset composite material substantially fills a gap  211   b  between two adjacent housing components  212   b ,  212   f . In some cases, the housing component  214   b  is formed from the thermoset composite material and the housing components  212   b ,  212   f  are formed from a material other than the thermoset composite material. In embodiments, the housing component  214   b  structurally couples the two adjacent housing components  212   b  and  212   f . The housing component  214   b  defines a portion  206   h  of the exterior surface  206  of the housing and a portion  207   h  of the interior surface  207  of the housing. 
     As shown in  FIG.  2 A , the housing component  212   b  defines a portion  206   b  of the exterior surface  206  of the housing and a surface  208   b  extending inward from the portion  206   b  of the exterior surface  206  towards the interior surface  207   b  of the electronic device. Similarly, the housing component  212   f  defines a portion  206   f  of the exterior surface  206  and a surface  208   f  extending inward from the portion  206   f  of the exterior surface  206  towards the interior surface  207   f  of the electronic device. The exterior surface  206  may be a side surface of the electronic device. The gap  211   b  is defined between the surfaces  208   b  and  208   f . The surfaces  208   b  and  208   f  may also be referred to herein as bonding surfaces. 
       FIG.  2 A  shows the width (w) of the gap and the thickness (t) of the gap. In some examples, the width of the gap may be from about 40 microns to about 300 microns, from about 100 microns to about 500 microns, from about 500 microns to about 2 mm, from about 1 mm to about 5 mm, or from about 5 mm to about 1 cm. The thickness (which may also be referred to as the depth) of the gap may be about 250 microns to about 2 mm, from about 250 microns to about 1 mm, from about 500 microns to about 1.5 microns, or from about 1 mm to about 5 mm. 
     In the example of  FIG.  2 A , the thickness of the gap is about the same as a thickness of the housing component  214   b  and also is about the same as a thickness of the housing components  212   b  and  212   f . In some cases, the portions  206   b ,  206   f , and  206   h  are substantially flush with one another, which can be achieved at least in part by co-machining the housing component  214   b  and the housing components  212   b  and  212   f . In additional examples, the depth of the gap is less than a thickness of the housing component, as shown in  FIG.  15 C . In further examples, a thickness of the housing component including a thermoset composite material (as measured from its exterior surface) may be greater than a thickness of the adjacent housing components, as shown in  FIGS.  8  and  9   . 
     The housing  210  may also be described as defining a side wall (or “sidewall”) of the electronic device, the housing component  212   b  defining a first portion of the side wall, and the housing component  212   f  defining a second portion of the side wall. The surface  208   b  may also be described as being defined by an end of the housing component  212   b  and the surface  208   f  described as being defined by an end of the housing component  212   f.    
     In some examples, the housing component  214   b  is formed from a thermoset composite material. The housing component  214   b  may therefore be referred as a thermoset composite housing component. The housing component  214   b  may be a dielectric housing component. The thermoset composite material may be as previously described with respect to  FIGS.  1 A to  1 B  and, for brevity, that description is not repeated here. However, this example is not limiting and in other examples only a portion of the housing component may be formed from the thermoset composite material. In particular,  FIG.  9    shows an example of a housing component formed from two different materials, such as a first thermoset composite material including particulate reinforcements and a second thermoset composite material including fibrous reinforcements. 
     Each of the housing components  212   b  and  212   f  are formed from a material other than the thermoset composite material. In some examples, each of the housing components  212   b  and  212   f  are formed from a metal, a glass, a glass-ceramic, a ceramic, or a combination of these materials. In some cases, the housing component  214   b  may be configured to be a window for an RF component positioned within the housing, such as when the housing component  214   b  is substantially transparent to RF and when the housing components  212   b  and  212   f  are formed from a metal or a ceramic having a high dielectric constant (e.g., zirconia). In additional cases, the housing component  214   b  may be configured to electrically isolate housing components  212   b  and  212   f , such as when both of housing components  212   b  and  212   f  are formed from a metal and at least one of  212   b  and  212   f  is configured to operate as an antenna. For example, at least one of the two metal housing components  212   b  and  212   f  may be configured to radiate electromagnetic radiation for a wireless communication system. 
       FIG.  2 B  shows an example of a detail view of the area  1 - 1  of the housing  210  of  FIG.  2 A . In particular,  FIG.  2 B  shows an interface region  260  between the housing component  214   b  and the housing component  212   f . As previously described, the housing component  214   b  may be formed from the thermoset composite material and the housing component  212   f  may be formed from a material other than the thermoset composite material. The interface region  260  includes the surface  208   f  defined by the housing component  212   f . As shown in  FIG.  2 B , the surface  208   f  defines a texture. As described in more detail with respect to  FIG.  16   , the surface  208   f  may be textured by various methods including mechanical texturing and/or chemical etching. The texture may be described as defining a plurality of texture features, such as peaks and valleys. In some embodiments, the root mean square height of the texture is from 0.5 microns to 2 microns, from 250 nm to 1 micron, or from 125 nm to 750 nm. In some cases, the polymerizable mixture which is cured to form the thermoset composite material can at least partially conform to the texture of the surface  208   f . When the polymerizable mixture is cured, the conforming of the thermoset composite material to the texture can create mechanical interlocks on the scale of the texture (e.g., micro-scale or smaller). In additional embodiments the surface  208   f  may define a smooth texture having a lower root mean square height (e.g., less than 125 nm) obtained through a polishing operation. 
       FIG.  2 C  shows an example of detail view of the area  2 - 2  of  FIG.  2 B . In the example of  FIG.  2 C , the interface region  260  further includes an anodization layer  262 . When the housing component  212   f  is formed from a metal material, electrochemical oxidation of the metal material can produce an anodization layer  262 . The anodization layer is formed from a metal oxide and is typically thicker than a native oxide layer formed on the metal material. For example, an aluminum oxide layer may be formed on an aluminum alloy through anodization. For example, the anodization layer may have an average thickness from about 250 nm to about 2 microns or from about 500 nm to about 1.25 microns. In some cases, the anodization layer  262  may be porous. For example, the pores may have an average diameter from about 10 nm to about 100 nm or from about 25 nm to about 75 nm. In some cases, the polymerizable mixture which is cured to form the thermoset composite material can at least partially enter the pores of the anodization layer. When the polymerizable mixture is cured, the thermoset composite material within the pores may form a nano-scale (also referred to as nano-sized) mechanical interlock. In some examples, the component extends into a first set of nano-sized pores of a first anodization layer on a surface of a first housing component and into a second set of nano-sized pores of a second anodization layer on a surface of a second housing component. In additional examples, a sol-gel coating may be formed on the surface of the housing component; the sol-gel coating may include a silicon or metal oxide. 
     As shown in the example of  FIG.  2 C , the interface region  260  may further include a primer  264 . In some cases, the primer may include a coupling agent. The coupling agent may be configured to interact with both the anodization layer  262  and the thermoset composite material. In some cases, the coupling agent may be silane-based. For example, the coupling agent may be derived from an alkoxy silane such as a dialkoxy or trialkoxy silane. The alkoxy silane may be capable of interacting with the metal oxide, such as the metal oxide of the anodization layer  262 . The alkoxy silane may also include a functional group capable of interacting with one or more components of the polymerizable mixture. For example, the alkoxy silane may include an epoxy group when the thermoset composite material is epoxy-based. When the interface region includes a porous anodization layer, the coupling agent  264  may enter the pores of the anodization layer. However, some of the coupling agent  264  may remain on the surface of the anodization layer as illustrated in  FIG.  2 C . In additional examples a coupling agent may be used in the absence of an anodization layer and the coupling agent may be capable of interacting with a native oxide layer on the metal or with a sol-gel coating formed on the metal. 
     Alternatively, the interface region may include a primer which is free of a coupling agent. For example, the primer may be derived from a polymerizable mixture different from that used to form the thermoset composite material. In some cases, an epoxy-based primer may be used for both epoxy-based and polyurethane-based thermoset composite materials. 
       FIG.  2 D  is an example of a scanning electron microscope image showing an interface region  260  between an aluminum alloy housing component  212   f  and an epoxy-based composite component  214   b . The dotted line in  FIG.  2 D  has been added to generally indicate the position of an interface between the aluminum alloy housing component  212   f  and an anodization layer  262  formed on the aluminum alloy housing component  212   f . A region of primer  264  is visible at an interface between the anodization layer  262  and the epoxy-based composite component  214   b  (this region is circled in  FIG.  2 D ). The anodization layer is porous, with the nano-scale pore diameters. The image of  FIG.  2 D  is a back-scattered electron image of a cross-section through the interface region  260 . 
       FIG.  3    shows another example of a cross-sectional view of the device of  FIGS.  1 A- 1 B . In particular,  FIG.  3    shows another example of a housing  310 . The housing  310  includes a housing component  314   b  including a thermoset composite material positioned between two housing components  312   b ,  312   f  which are formed from a material other than the thermoset composite material. In some cases, the housing component  314   b  may be formed from the thermoset composite material. The cross-section through the housing  310  may be another example of a lateral cross-section through the housing  110  along A-A in  FIG.  1 A . The housing components  312   b ,  312   f , and  314   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b ,  112   f , and  114   b  and, for brevity, that description is not repeated here. 
     In the example of  FIG.  3   , each of the housing components  312   b  and  312   f  includes a retention feature  313 . The retention features  313  can structurally interlock with the housing component  314   b  and thus help mechanically retain the housing component  314   b  within the gap  311   b  (formed between the housing components  312   b  and  312   f ). In the example of  FIG.  3   , each of the retention features  313  defines a protrusion from an internal surface  307  of the housing  310 , the protrusion extending into the interior volume of the electronic device. The housing component  314   b  extends around the retention features  313  and, in some cases, may encapsulate the retention features  313 . As shown in  FIG.  3   , the retention features  313  define a hole  333  which extends through or partially through the protrusion and the housing component  314   b  may extend into the hole  333 . For example, the hole  333  may be oriented perpendicular to the plane of  FIG.  3   , parallel to the plane of  FIG.  3   , or at an intermediate angle. The example of  FIG.  3    is not limiting, and retention features may take a variety of forms, including depressions or grooves in a surface extending inward from the external surface (as shown in  FIGS.  5 - 6 ,  8 - 9 , and  14 B ), an internal angle (as shown in  FIGS.  6  and  8 - 9   ), protrusions which lack a hole such as  333 , and the like. 
     In some cases, a retention feature along a bonding surface is larger than the features produced by the surface modification techniques previously described (e.g., texture or pores). The retention feature may be created by a machining technique, a molding technique, another forming technique, or by combinations of forming techniques. In some cases, a retention feature may be used in combination with one or more of housing component surface modification techniques. As previously discussed, these surface modification techniques include, but are not limited to, mechanical texturing, chemical etching, anodization, use of a primer, and the like. 
       FIG.  4    shows another example electronic device. In the example of  FIG.  4   , the device  400  includes a housing  410  and a front cover  422 . In some cases, the device further includes a rear cover. The housing  410  and the front cover  422  may be part of an enclosure which encloses internal components of the electronic device. 
     The housing  410  includes some housing components which include a thermoset composite material (e.g.,  414   a ,  414   b , and  415 ) and other housing components which are formed from a material other than the thermoset composite material (e.g.,  412   a ,  412   b , and  412   c ). In some cases, one or more of the housing components  414   a ,  414   b , and  415  may be formed from the thermoset composite material. The housing components  414   a ,  414   b , and  415  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and, for brevity, that description is not repeated here. In addition, the housing components  412   a ,  412   b , and  412   c  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     In the example of  FIG.  4   , the housing component  412   a  defines an opening (e.g.,  511  as shown in the cross-section view of  FIG.  5   ). In the example of  FIG.  4   , the opening has the form of a slot along the side surface  406 . The housing component  415  including the thermoset composite material is positioned within the opening and bonded to the housing component  412   a . The housing  410  may at least partially surround an emitter, a receiver, and/or a transceiver. When the housing component  412   a  is formed from an electrically conducting material, the housing component  415  may provide a “window” for the emitter, receiver, and/or transceiver. In some cases, the housing component  415  may provide a window for a millimeter wave antenna that is configured to conduct 5G communications. For example, the antenna may have a 24 GHz to 39 GHz frequency band or a 60 GHz frequency band (e.g., 57-64 GHz or 64-71 GHz). In addition, the housing component  415  may define a portion of a waveguide or allow for beam-forming or beam directing functionality. In additional embodiments, the opening may be configured to operate as an emitter for a wireless communication system and the housing component  412   a  may be operably coupled to wireless transmission circuitry. The electronic device  400  also includes an input device  438 , which may have the form of a button. 
     The housing component  412   a  may also be described as having a wall which defines at least a portion of the opening (e.g., the wall defining the surfaces  508   a  and  508   b  as shown in the cross-section view of  FIG.  5   ). The surface(s) of the wall may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . In some cases, the wall is textured. For example, a textured wall of a housing component formed from a metal may result from forming texture features into the metal, by forming a coating having a texture on or into the metal, or by combinations thereof. In addition, the housing component  412   a  may include a retention feature as previously described with respect to  FIG.  3   . For brevity, the description previously provided with respect to  FIGS.  2 A- 2 C and  3    is not repeated here. 
     In addition, the housing component  414   a  including a thermoset composite material may mechanically or structurally couple the housing components  412   a  and  412   b  and the housing component  414   b  may mechanically or structurally couple the housing components  412   a  and  412   c . As previously discussed with respect to  FIGS.  1 A and  1 B , the housing components  414   a  and  414   b  may provide windows for an emitter, a receiver, and/or a transceiver internal to the electronic device or may electrically isolate adjacent electrically conductive components (at least one of which may be configured to operate as an antenna). For brevity, the description previously provided with respect to  FIGS.  1 A and  1 B  is not repeated here. 
     The front cover  422  may be positioned over a display  442  and may provide a window through which the display may be viewed. In some embodiments, the display  442  may be attached to (or abut) the front cover  422 . The front cover  422  may define a front surface  402  of the electronic device. The front cover  422  may be similar to the front cover  122  and, for brevity, that description is not repeated here. An opening  434  may be provided in the front cover  422  and in some cases may provide a speaker port. 
       FIG.  5    shows an example of a cross-sectional view of the electronic device  400  of  FIG.  4   . In particular,  FIG.  5    shows an example of a housing  510 . The housing  510  includes a housing component  515  including a thermoset composite material positioned in an opening  511  of the housing component  512  which is formed from a material other than the thermoset composite material. The cross-section through the housing  510  may be an example of a vertical cross-section through the housing  410  along B-B in  FIG.  4   . The housing component  515  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and the housing component  512  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   a  and  112   f  and, for brevity, that description is not repeated here. 
     In the example of  FIG.  5   , the housing component  515  including the thermoset composite material substantially fills an opening  511  in a housing component  512  which is formed from a material other than the thermoset composite material. In some cases, the housing component  515  may be formed from the thermoset composite material. In embodiments, the housing component  515  is a dielectric housing component and the housing component  512  is an electrically conductive housing component. In embodiments, the housing component  515  is a structural component of the housing  510 . The housing component  512  defines portions  506   a  and  506   b  and the housing component  515  defines a portion  506   c  of the exterior surface  506  of the housing. The exterior surface  506  may be a side surface of the electronic device, as shown in  FIG.  4   . 
     As shown in  FIG.  5   , the housing component  512  also defines a surface  508   a  extending inward from the portion  506   a  of the exterior surface  506  towards the interior surface  507 . In addition, the housing component  512  defines a surface  508   b  extending inward from the portion  506   b  of the exterior surface  506 , towards the interior surface  507 . The opening is defined at least in part between the surfaces  508   a  and  508   b , which generally face each other. The housing component  515  is bonded to the surfaces  508   a  and  508   b , which may also be referred to herein as bonding surfaces. The surface(s)  508   a  and  508   b  may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . 
     In the example of  FIG.  5    the housing component also defines retention features  513  along the surfaces  508   a  and  508   b . In particular, the retention features  513  define a curved depression along the surfaces  508   a  and  508   b , which may also be referred to herein as an undercut. In the example of  FIG.  5   , the depression extends along the length of the surfaces  508   a  and  508   b  (and the depth of the opening  511 ). However, this example is not limiting and in other examples the depression may extend along a lesser portion of the surfaces  508   a  and  508   b  (as shown in  FIG.  6   ) and/or may have a different shape. 
       FIG.  6    shows an additional example of a cross-sectional view of the electronic device  400  of  FIG.  4   . In particular,  FIG.  6    shows an example of a housing  610 . The housing  610  includes a housing component  615  including a thermoset composite material positioned in an opening  611  of a housing component  612  which is formed from a material other than the thermoset composite material. The cross-section through the housing  610  may be another example of a vertical cross-section through the housing  410  along B-B in  FIG.  4   . The housing component  615  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and the housing component  612  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     In the example of  FIG.  6   , the housing component  615  including the thermoset composite material substantially fills an opening  611  in a housing component  612  which is formed from a material other than the thermoset composite material. In some cases, the housing component  615  may be formed from the thermoset composite material. In embodiments, the housing component  615  is a dielectric housing component and the housing component  612  is an electrically conductive housing component. In embodiments, the housing component  615  is a structural component of the housing  610 . In a similar fashion as previously described for  FIG.  5   , the housing component  612  may define first and second portions  606   a ,  606   b  and the housing component  615  may define a third portion  606   c  of the exterior surface  606  of the housing. The exterior surface  606  may be a side surface of the electronic device, as shown in  FIG.  4   . 
     As shown in  FIG.  6   , the housing component  612  also defines a surface  608   a  and a surface  608   b , which generally face each other. The opening  611  is defined at least in part between the surfaces  608   a  and  608   b . The housing component  615  is bonded to the surfaces  608   a  and  608   b , which may also be referred to herein as bonding surfaces. The surface(s)  608   a  and  608   b  may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . 
     In the example of  FIG.  6    the housing component  612  also defines retention features  613   a  and  613   b  along the surfaces  608   a  and  608   b . In particular, the retention features  613   a  and  613   b  each define a curved depression in the surfaces  608   a  and  608   b . The retention features  613   a  and  613   b  may also be characterized as an “undercut.” The retention features  613   a  and  613   b  each define an angled portion of the surfaces  608   a  and  608   b . In the example of  FIG.  6   , the angled portion defined by retention feature  613   b  forms an angle having a magnitude greater than zero and less than ninety degrees with respect to an adjacent portion of the surface (and a line perpendicular to  606   c ). As a result, the portion of the component  615  defining an interior surface  607  of the housing is offset with respect to the portion of the component  615  which defines the portion  606   c  of the exterior surface  606 . However, this example is not limiting and in other examples an angled portion may define an angle having a magnitude greater than zero and less than or equal to ninety degrees or greater than or equal to ninety degrees and less than one hundred eighty degrees. 
       FIGS.  7 A and  7 B  show views of an additional example electronic device. In the example of  FIGS.  7 A and  7 B , the device  700  includes a housing  710  and a front cover  722 . The housing  710  and the front cover  722  may be part of an enclosure which encloses internal components of the electronic device. In the example of  FIGS.  7 A and  7 B , the dimensions and form factor, including the ratio of the length of its long sides to the length of its short sides, correspond to those of a tablet computing device. 
     In the example of  FIGS.  7 A and  7 B , the housing  710  includes housing components which include a thermoset composite material (e.g.,  714  and  715 ). In some cases, the housing components  714  and  715  are formed from the thermoset composite material and may be referred to as thermoset composite housing components. One or more other housing components are formed from a material other than the thermoset composite material (e.g., one or more housing components defining the housing portions  712   a ,  712   b ,  712   c , and  712   d ). In embodiments, the housing components  714  and  715  are dielectric housing components and the one or more housing components defining the housing portions  712   a ,  712   b ,  712   c , and  712   d  are one or more electrically conductive housing components. The housing components  714  and  715  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and, for brevity, that description is not repeated here. In addition, the one or more housing components defining the housing portions  712   a ,  712   b ,  712   c , and  712   d  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     The housing component  714  extends along a rear surface  704  of the electronic device  700 . In the example of  FIGS.  7 A and  7 B , the housing component  714  also extends along one or more side surfaces  706  of the electronic device. Similarly, the housing component  715  may extend along the rear surface  704  and a side surface  706  of the electronic device  700 . 
     In the example of  FIGS.  7 A and  7 B , the housing  710  comprises one or more housing components formed from a material other than the thermoset composite material. In some cases, the different housing portions  712   a ,  712   b , and  712   c  are formed by a single housing component. In other cases, the different housing portions  712   a ,  712   b , and  712   c  are formed by different housing components, as is explained further below. 
     As an example, the housing portions  712   a ,  712   b , and  712   c  may be formed by a single housing component. A gap between the housing portions  712   a  and  712   b  may appear as shown in  FIG.  8    in locations where a slot is formed through the housing component. However, the slot which defines the gap may not extend through the housing component in other locations, allowing electrical contact between the housing portions  712   a  and  712   b  in these locations. Each of the housing components  714  and  715  may assist in mechanically or structurally coupling other portions of the housing  710 . For example, the housing component  714  may assist in mechanically and structurally coupling the different housing portions  712   a ,  712   b , and  712   c.    
     In additional examples, the housing portion  712   a  may be formed by a first housing component and the housing portion  712   b  may be formed by a second housing component. A gap (e.g.,  811  of  FIG.  8   ) may be formed between the housing portions  712   a  and  712   b  and the housing component  714  may be introduced into the gap. When the housing portions  712   a  and  712   b  are formed of an electrically conductive material, the housing component  714  may electrically isolate the housing portion  712   a  from the housing portions  712   b  and  712   c  (e.g., to prevent electrical conduction or communication through the housing component  714 ). Each of the housing components  714  and  715  may mechanically or structurally couple the different components of the housing  710  which are formed from a material other than the thermoset composite material. For example, the housing component  714  may mechanically and structurally couple different housing components which define housing portions  712   a ,  712   b , and  712   c.    
     At least one of the housing portions  712   a ,  712   b , and  712   c  may be configured to operate as an antenna. For example, the electronic device may comprise wireless transmission circuitry that is operably coupled to at least one of the housing portions  712   b  and  712   c . In examples where each of the housing portions  712   a ,  712   b , and  712   c  is defined by a different housing component, at least one of these housing components may be configured to operate as an antenna. 
     Alternately or additionally, the housing component  714  and/or  715  comprising the thermoset composite material may provide a window for an emitter and/or a receiver internal to the electronic device. For example, the housing component  714  and/or  715  may provide a window for an RF emitter, an RF receiver, and/or an RF transceiver. The RF emitter, RF receiver and/or RF transceiver may be part of a wireless communication system. 
     The example of  FIGS.  7 A and  7 B  is not limiting and in additional embodiments, the housing may comprise at least one housing component that includes a thermoset composite material and at least one housing component that is formed from a material other than the thermoset composite material. In some cases, a housing component including a thermoset composite material may extend exclusively along one surface of the electronic device, such as a rear surface of the electronic device. 
     The front cover  722  may be positioned over a display  742 , and may provide a window through which the display may be viewed. In some embodiments, the display  742  may be attached to (or abut) the front cover  722 . The front cover  722  may define a front surface  702  of the electronic device  700 . The front cover  722  may be similar to the front cover  122  and, for brevity, that description is not repeated here. The electronic device may also include a thicker region  744  along the rear surface  704  of the electronic device, which may be similar to the region  144 . The region  744  may accommodate one or more optical modules  752  of a camera assembly. The region  744  may also accommodate a sensor  754 , such as a LiDAR sensor, and other components  753  such as a microphone, a smaller optical component such as a flash, and so forth. In the example of  FIGS.  7 A and  7 B  input devices  737  and  738  are provided along the side surface  706  of the device  700 . 
       FIG.  8    shows an example of a cross-sectional view of the electronic device  700  of  FIGS.  7 A and  7 B . In particular,  FIG.  8    shows an example of a housing  810 , which may be an example of the housing  710 . The housing  810  includes a housing component  814  including a thermoset composite material. The housing component  814  may be formed from the thermoset composite material. 
     At least a portion of the housing component  814  is positioned in a gap  811  defined between the housing portions  812   a  and  812   b , each of which is formed from a material other than the thermoset composite material. The housing component  814  may be a dielectric housing component and the housing portions  812   a  and  812   b  may be an electrically conducting housing portions. The cross-section through the housing  810  may be an example of a lateral cross-section through the housing  710  along C-C in  FIG.  7 B . The housing component  814  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and the housing portions  812   a  and  812   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     In the example of  FIG.  8   , the housing component  814  including the thermoset composite material substantially fills a gap  811  between the housing portions  812   a  and  812   b , each of which is formed from a material other than the thermoset composite material. In embodiments, the housing component  814  is a structural component of the housing  810 . In the example of  FIG.  8   , the housing component  814  provides structural integrity to the housing not only by substantially filling the gap  811  but also by providing support to the housing portion  812   a  in the vicinity of gap. As shown in  FIG.  8   , the thickness t 2  of the housing portion  814  is greater than a thickness t 1  of the housing portion  812   a , enabling it to provide support to the housing portion  812   a.    
     In a similar fashion as previously described for  FIG.  2 A , the housing portions  812   a  and  812   b  may define first and second portions and the housing component  814  may define a third portion of the exterior surface  806  of the housing. The exterior surface  806  may be a rear surface of the electronic device, as shown in  FIG.  7   . In some cases, the first, second, and third portions of the exterior surface  806  are substantially flush with one another, which can be achieved at least in part by co-machining the housing portions  812   a ,  812   b , and the housing component  814 . Similarly, the housing portions  812   a  and  812   b  may define first and second portions and the housing component  814  may define a third portion of the interior surface  807  of the housing. In addition, the housing component  814  extends along a portion of the interior surface of each of the housing portion  812   a  and the housing portion  812   b.    
     As shown in  FIG.  8   , each of the housing portions  812   a  and  812   b  also defines a surface ( 808   a ,  808   b ) extending inward from the exterior surface  806  towards the interior surface  807 . The housing component  814  is bonded to the surfaces  808   a  and  808   b , which may also be referred to herein as bonding surfaces. The housing component  814  may also be bonded to the portions of the interior surface  807  of the housing (e.g., a portion of the interior surface of each of the housing portion  812   a  and the housing portion  812   b ). One or more of the surface(s)  808   a  and  808   b  and portions of the interior surface  807  (e.g., portions along which the housing component  814  extends) may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . In the example of  FIG.  8   , each of the housing portions  812   a  and  812   b  also define one or more retention features such as a recess and/or an angled portion. For example, the housing component  814  extends into the recess formed into the housing portion  812   b . These retention features may be similar to those previously described with respect to  FIGS.  1 A to  1 B,  3 , and  5 - 6    and, for brevity, that description is not repeated here. 
       FIG.  9    shows another example cross-sectional view of the device of  FIGS.  7 A- 7 B . In particular,  FIG.  9    shows an example of a housing  910 , which may be an example of the housing  710 . The housing  910  includes a housing component  914  including a thermoset composite material. At least a portion of the housing component  914  is positioned in a gap  911  defined between the housing portions  912   a  and  912   b , each of which is formed from a material other than the thermoset composite material. The housing component  914  may be a dielectric housing component and the housing portions  912   a  and  912   b  may be an electrically conducting housing portions. The cross-section through the housing  910  may be an example of a lateral cross-section through the housing  710  along C-C in  FIG.  7 B . 
     In the example of  FIG.  9   , the housing component  914  includes a first portion  914   a  which is formed from the thermoset composite material and a second portion  914   b  which is formed from a material other than the thermoset composite material of the portion  914   a . In some cases, the second portion  914   b  may have a greater strength than the first portion  914   a  and the first portion  914   a  may be used as an inlay to provide a desired color and/or surface finish to the housing component  914 . In some cases, a thickness of the first portion  914   a  is less than that of the second portion  914   b . For example, the second portion  914   b  may have a thickness which is at least twice that of the first portion  914   a.    
     In some cases, the second portion  914   b  is formed from a composite material including discontinuous reinforcing fibers in a matrix of a polymer material. In some cases, the matrix is formed from a thermoset polymer, such as an epoxy-based or polyurethane-based polymer. This composite material may therefore be an additional thermoset composite material. The reinforcing fibers may be glass fibers (e.g., fiberglass), carbon fibers, metal nanowires, aramid fiber, and/or other fiber or wires. In some examples, the fibers may have a diameter from about 3 microns to about 25 microns. In some cases, the loading of the fibers in the matrix is from about 20 vol % to about 40 vol %. In some examples, the composite materials of each of the first portion  914   a  and the second portion  914   b  have a matrix which is epoxy-based. The first portion  914   a  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and the housing portions  912   a  and  912   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     As previously described with respect to  FIG.  8   , the housing component  914  substantially fills the gap  911  and extends along portions of the interior surface of each of the housing portions  912   a  and  912   b . In the example of  FIG.  9   , the housing component  914  provides structural integrity to the housing not only by substantially filling the gap  911  but also by providing support to the housing portion  912   a  in the vicinity of gap. 
     In a similar fashion as previously described for  FIG.  8   , the housing portions  912   a  and  912   b  may define first and second portions and the housing component  914  may define a third portion of the exterior surface  906  of the housing. Similarly, the housing portions  912   a  and  912   b  may define first and second portions and the housing component  914   b  may define a third portion of the interior surface  907  of the housing. In addition, each of the housing portions  912   a  and  912   b  also defines a surface ( 908   a ,  908   b ) extending inward from the exterior surface  906 . The housing component  914  is bonded to these surfaces. The housing component  914  may also be bonded to the portions of the interior surface  907  of the housing. One or more of these surface(s) may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . In addition, each of the housing portions  912   a  and  912   b  defines one or more retention features such as a depression and/or an angled portion. These retention features may be similar to those previously described with respect to  FIGS.  1 A to  1 B,  3 , and  5 - 6    and, for brevity, that description is not repeated here. 
       FIG.  10    shows a further example electronic device. In the example of  FIG.  10   , the device  1000  includes an enclosure  1010  which includes a housing  1012  and a component  1014 . The component  1014  may provide a window for an internal device component (such as the device component  1170  shown in  FIG.  11   ). The housing  1012  defines an exterior surface  1002  and an exterior surface  1006 . In some cases, the device  1000  may form a rear cup for a pair of headphones. The electronic device  1000  may further include an ear cushion which attaches to an end of the housing  1012  (e.g., generally opposite the exterior surface  1002 ). The exterior surface  1006  may extend between the exterior surface  1002  and the additional ear cushion. An ear band may also attach to the housing  1012  (e.g., along the surface  1006 ). The housing  1012  may at least partially enclose internal components of the electronic device. 
     The enclosure  1010  includes a component  1014  which includes a thermoset composite material and a housing  1012  which is formed from a material other than the thermoset composite material. In some cases, the component  1014  may be formed from the thermoset composite material. The component  1014  may be a dielectric component and the housing  1012  may be an electrically conducting housing. The component  1014  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and, for brevity, that description is not repeated here. In addition, the housing  1012  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     The housing  1012  defines an opening (e.g.,  1111  as shown in the cross-section view of  FIG.  11   ). The component  1014  including the thermoset composite material is positioned within the opening and bonded to the housing  1012 . The housing  1012  may at least partially surround an emitter and/or receiver. When the housing  1012  is formed from an electrically conducting material, the component  1014  may provide a “window” for the emitter, receiver, and/or transceiver in some embodiments. 
     In the example of  FIG.  10   , the opening  111  is defined between a first portion  1012   a  and a second portion  1012   b  of the housing  1012 . The first portion  1012   a  defines a first portion and the second portion  1012   b  defines a second portion of the exterior surface  1006  of the housing  1012 . The example of  FIG.  10    is not limiting and in other examples the housing  1012  may have a different shape. For example, the exterior surface  1002  may define a shape that is less square and closer to an oval and the exterior surface  1006  may have a greater height relative to the length and width of the surface  1002 . Further, an opening may alternately or additionally be included in a different surface of the housing than shown in the example of  FIG.  10   . 
     The housing  1012  may also be described as having a wall which defines at least a portion of the opening (e.g., the wall defining the surfaces  1108   a  and  1108   b , which in turn define the opening  1111  as shown in the cross-section view of  FIG.  11   ). The surface(s) of the wall may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . In addition, the housing  1012  may include a retention feature as previously described with respect to  FIG.  3   . For brevity, the description previously provided with respect to  FIGS.  2 A- 2 C and  3    is not repeated here. 
       FIG.  11    shows an example of a cross-sectional view of the electronic device  1000  of  FIG.  10   . In particular,  FIG.  11    shows an example of an enclosure  1110 . The enclosure  1110  includes a component  1114  including a thermoset composite material positioned in an opening  1111  of a housing  1112  which is formed from a material other than the thermoset composite material. In some cases, the component  1114  may be formed from the thermoset composite material. In some cases, the component  114  is a dielectric component and the housing  112  is an electrically conducting housing. The cross-section through the enclosure  1110  may be an example of a vertical cross-section through the enclosure  1010  along D-D in  FIG.  10   .  FIG.  11    also shows a device component  1170  positioned behind the component  1114 . The component  1114  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and the housing  1112  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     In the example of  FIG.  11   , the component  1114  including the thermoset composite material substantially fills an opening  1111  in a housing  1112 , which is formed from a material other than the thermoset composite material. In embodiments, the component  1114  is a structural component of the enclosure  1110 . The housing  1112  includes the portions  1112   a  and  1112   b , which at least partially define the opening  1111 . The portion  1112   a  of the housing  1112  defines a portion  1106   a , the portion  1112   b  defines a portion  1106   b , and the component  1114  defines a portion  1106   c  of the exterior surface  1106  of the housing. In the example of  FIG.  11   , the portion  1106   a , the portion  1106   b , and the portion  1106   c  of the exterior surface  1106  together define a curved region of the exterior surface  1106 . In addition, the portions  1112   a  and  1112   b  of the housing  1112  and the component  1114  together define a curved region of the interior surface  1107 . The exterior curved region may define a convex curve and the interior curved region may define a convex curve in the plane of a vertical cross-section through the housing  1112 . 
     As shown in  FIG.  11   , the portion  1112   a  of the housing  1112  also defines a surface  1108   a  extending inward from the portion  1106   a  of the exterior surface  1106  (towards the interior surface  1107 ). In addition, the portion  1112   b  of the housing  1112  defines a surface  1108   b  extending inward from the portion  1106   b  of the exterior surface  1106 . The opening is defined at least in part between the surfaces  1108   a  and  1108   b , which generally face each other. The component  1114  is positioned between and bonded to the surfaces  1108   a  and  1108   b , which may also be referred to herein as bonding surfaces. The surface(s)  1108   a  and  1108   b  may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . 
     In some cases, the component  1114  provides a transmissive window for a device component  1170 . The device component  1170  may be an emitter component, a receiver component, or a transceiver component. In some embodiments, the device component  1170  is part of a wireless communication system. As examples, the wireless communication system may be a radio-frequency or an infrared communication system and the device component  1170  may include one or more antennas. In additional cases, the device component  1170  may be a sensor. For example, the sensor may be a magnetic sensor, a radio-frequency identification chip, a Hall-effect sensor, or the like. In an additional example, the device component  1170  may include a mm wave antenna that is configured to conduct 5G communications. In addition, the component  1114  may define a portion of a waveguide or allow for beam-forming or beam-directing functionality. 
       FIG.  12    shows an example of a wearable electronic device. For example, the device  1200  may be a watch. The device  1200  includes a housing  1210 , a front cover  1222 , and a rear cover  1224 . The front cover  1222  may define a front surface  1202  of the device and the housing  1210  may define a side surface  1206  of the device. A band  1225  may be attached to the housing  1210  and configured to secure the wearable electronic device to a user. 
     In the example of  FIG.  12   , the housing  1210  includes multiple housing components (e.g.,  1214   a ,  1214   b ) including a thermoset composite material. The housing components  1214   a  and  1214   b  may be formed from a thermoset composite material. The housing  1210  also includes multiple housing components (e.g.,  1212   a ,  1212   b ,  1212   c ) formed of a material other than the thermoset composite material. The housing components  1214   a  and  1214   b  may be dielectric housing components and the components  1212   a ,  1212   b , and  1212   c  may be electrically conducting housing components. The housing components  1214   a  may mechanically or structurally couple the housing components  1212   a  and  1212   b  and the housing component  1214   b  may mechanically or structurally couple the housing components  1212   a  and  1212   c . As previously discussed with respect to  FIGS.  1 A and  1 B , the housing components  1214   a  and  1214   b  may electrically isolate adjacent electrically conductive components. For example, some degree of electrical isolation of the housing components  1212   a  and  1212   b  may be desirable when at least one of the housing components  1212   a  and  1212   b  is configured to radiate electromagnetic radiation. The housing components  1214   a  and  1214   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b  and, for brevity, that description is not repeated here. In addition, the housing components  1212   a ,  1212   b , and  1212   c  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f  and, for brevity, that description is not repeated here. 
     The device  1200  further includes input members  1238  and  1239 . The input member  1239  may be part of a crown module of the electronic device  1200 . As discussed further with respect to  FIG.  13   , in some cases the input member  1239  includes a component (e.g.,  1314 ) including a thermoset composite material. The input member  1239  has an outer surface configured to receive a rotary user input and also is configured to receive input in the form of a “press.” In addition, the input member  1239  may provide an electrode for a biosensor within the electronic device  1200 . For example, the input member  1239  may include an electrode which can be used for taking an electrocardiogram. The housing  1210  can form one or more other electrodes for taking the electrocardiogram or a conductive terminal may be formed on the housing to serve as the other electrode. A crown module may be positioned at least partially within an aperture formed within the housing  1210 . 
     The front cover  1222  may be positioned over a display  1242 , and may provide a window through which the display may be viewed. In some cases, the display  1242  is a touch-sensitive display. In some embodiments, the display  1242  may be attached to (or abut) the front cover  1222 . In some cases, the front cover  1222  may include a flat middle portion larger than the viewable area of the display and a curved edge portion surrounding the flat middle portion. The curved edge portion may coincide with a curved exterior surface of the housing to form a continuous contoured surface. The front cover  1222  may be formed from similar materials as the front cover  122  and, for brevity, that description is not repeated here. 
       FIG.  13    is an example cross-sectional view of the device of  FIG.  12   . In particular,  FIG.  13    shows an example of an input member  1339 . The input member  1339  includes a component  1314  including a thermoset composite material. In some cases, the component  1314  may be formed from the thermoset composite material. Each of the components  1312   a  and  1312   b  are formed from a material other than the thermoset composite material. The component  1314  may be a dielectric component and the components  1312   a  and  1312   b  may be electrically conducting components. The input member further defines a shaft  1340 , which may extend into the housing (e.g.,  1210  in  FIG.  12   ). 
     At least a portion of the component  1314  is positioned in a gap  1311  defined between the components  1312   a  and  1312   b . The component  1314  may mechanically and structurally couple the components  1312   a  and  1312   b . In embodiments, the component  1314  is a structural component of the input member  1339 . The component  1314  may define a ring, as shown in  FIG.  12   . 
     In embodiments when the components  1312   a  and  1312   b  are formed from an electrically conducting material such as a metal, the component may also electrically isolate adjacent electrically conductive housing components. For example, the component  1312   b  may serve as an electrode for a biosensor within the electronic device. Electrical isolation of the component  1312   b  from the component  1312   a  may facilitate operation of the biosensor by reducing opportunities for unintended contact between the electrode and user. In some cases, the electrode can be used for taking an electrocardiogram. The housing can form one or more other electrodes for taking the electrocardiogram or a conductive terminal may be formed on the housing to serve as the other electrode. The cross-section through the input member  1339  may be an example of a vertical cross-section through the input member  1239  along E-E in  FIG.  12   . 
     In some examples, the component  1314  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b . However, in other examples the component  1314  may be able to have a lower glass transition temperature and strength than the housing component  114   b  in order to decrease the cure temperature and/or decrease the cure time. The components  1312   a  and  1312   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f . For brevity, the description of physical properties, electrical properties, and other properties of the housing components  114   b ,  112   b , and  112   f  is not repeated here. 
     The components  1312   a  and  1312   b  may define first and second portions and the component  1314  may define a third portion of the exterior surface  1306  of the input member  1339 . In some cases, the first, second, and third portions of the exterior surface  1306  are substantially flush with one another, which can be achieved at least in part by co-machining the housing components  1312   a ,  1312   b , and  1314 . 
     As shown in  FIG.  13   , each of the housing components  1312   a  and  1312   b  also defines a surface extending inward from the exterior surface  1306  towards the interior surface  1307 . The housing component  1314  is bonded to these surfaces, which may also be referred to herein as bonding surfaces. One or more of the surfaces may be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like as previously described with respect to  FIGS.  2 A- 2 C . 
       FIGS.  14 A and  14 B  show an example of an electronic device  1400 , with  FIG.  14 B  showing an example cross-sectional view of  FIG.  14 A  along F-F. The device  1400  includes an enclosure  1410 . The enclosure  1410  comprises a component  1414  including a thermoset composite material, which is placed near a corner  1411  of the enclosure. The component  1414  may be a dielectric component. The component  1414  may provide a window for a device component internal to the enclosure (as shown in  FIG.  14 B ). Corners of the enclosure  1410  may have a greater tendency to experience impact during a drop event, but the component  1414  is configured to have sufficient impact resistance to be located near a corner. As previously discussed, the component  1414  may be configured to have sufficient ductility and strength to provide the enclosure  1410  with structural integrity. In some examples, the component  1414  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b.    
     The enclosure  1410  also includes a housing  1412  formed from a material other than a thermoset composite material. For example, the housing  1412  may be formed from a metal, a glass, a glass-ceramic, a ceramic, or a combination of these materials. In some cases, the housing  1412  is an electrically conducting housing. In some examples, the housing  1412  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f.    
     When the housing  1412  is formed from an electrically conductive material, the component  1414  may be positioned over an emitter component (also referred to herein as an emitting component, a radiating component or simply as an emitter), a receiver component (also referred to herein as a receiving component or simply as a receiver), a transceiver component, or a sensor component (also referred to herein as a sensing component) positioned within the housing  1410 ).  FIG.  14 B  shows a device component  1470  positioned within the housing. 
     The housing  1412  includes a front wall  1422 , a rear wall  1424 , and four side walls. Sidewalls  1426   a  and  1426   b  are shown in  FIG.  14 A . In the example of  FIG.  14 A , the housing  1412  defines four corners. A corner  1411  of the housing  1412  may correspond to a region or portion of the housing in which one side (e.g.,  1426   a ) transitions to another side (e.g.,  1426   b ). The corners are shown to be rounded in  FIG.  14 A  but may alternatively be square or have another profile shape (e.g., a squared or angled corner). 
     In the example of  FIG.  14 A , the component  1414  is positioned on the sidewall  1426   a  proximate the corner  1411 . The component  1414  may define a first portion of the sidewall  1426   a  while the housing  1412  may define a second portion of the sidewall  1426   b.    
       FIG.  14 B  shows an example cross-sectional view of the device  1400  of  FIG.  14 A . The cross-section extends through the component  1414  and through portions of the sidewalls  1426   a  and  1426   b . As shown in  FIG.  14 B , the electronic device  1400  also includes a device component  1470  positioned behind the housing component  1414 . In some cases, the housing component  1414  provides a transmissive window for the device component  1470 . 
     The device component  1470  may be an emitter component, a receiver component, a transceiver component, or a sensor component. In some embodiments, the device component  1470  is part of a wireless communication system. As examples, the wireless communication system may be a radio-frequency or an infrared communication system. In some cases, the device component  1470  may be an antenna. In additional embodiments, the device component  1470  may be a sensor. In further embodiments, the device component  1470  may be part of a wireless charging system, which may be an inductive coupling wireless charging system or an RF wireless charging system. For example, the device component may include a wireless receiver component such as a wireless receiver coil or other feature of the wireless charging system. The device component  1470  may be similar to the device component  1170  and, for brevity, that description is not repeated here. 
       FIGS.  15 A,  15 B, and  15 C  show another example electronic device  1500 . In  FIG.  15 A  the front cover  1522  and the sidewalls  1526   a  and  1526   b  of the device are visible. In  FIG.  15 B  the rear cover  1524  and the sidewalls  1526   a  and  1526   c  are visible.  FIG.  15 C  shows an example cross-sectional view through the front cover  1522 . 
     The device  1500  includes a housing  1510 . The housing  1510  comprises housing components  1514 ,  1516 , and  1518  including a thermoset composite material. The housing  1510  also includes first and second housing components  1512   a  and  1512   b  formed from a material other than a thermoset composite material. For example, the housing components  1512   a  and  1512   b  may be formed from a metal, a glass, a glass-ceramic, a ceramic, or a combination of these materials. In some embodiments, the housing components  1514 ,  1516 , and  1518  are dielectric housing components while the housing components  1512   a  and  1512   b  are electrically conductive housing components. The housing components  1514 ,  1516 , and  1518  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b . The housing components  1512   a  and  1512   b  may be similar in composition, physical properties, electrical properties, and other properties to the housing components  112   b  and  112   f.    
     In the example of  FIGS.  15 A and  15 B , the housing component  1516  is located centrally on a front wall  1522  of the housing, the housing component  1518  is positioned at least partially between the housing components  1512   a  and  1512   b , and the housing component  1514  is located centrally on a rear wall  1524  of the housing. The examples of  FIGS.  15 A to  15 C  are not limiting and in other examples the housing components  1514  and  1516  need not be located centrally on the front or the back wall and in some cases may be located onto a side wall of the housing  1510 . 
     As shown in  FIGS.  15 A and  15 B , the housing component  1518  is positioned at least partially between and bonded to the housing components  1512   a  and  1512   b . For example, the housing component may be positioned in a gap between the housing components  1512   a  and  1512   b  in a similar fashion as shown with respect to the examples of  FIGS.  2 A and  3   . As shown in  FIGS.  15 A and  15 B , the housing component extends around a perimeter of the housing  1510 . The housing component  1518  may be configured to have sufficient strength and impact resistance so that the housing  1510  maintains structural integrity. In some cases, use of the housing component  1518  to bond the housing components  1512   a  and  1512   b  may simplify assembly of the housing  1510 . 
     In some cases, the housing component  1514  may provide a transmissive window over an internal device component. For example, the housing component  1514  may form a transmissive window over an internal device component when the housing component  1512   b  is formed from an electrically conductive material. The internal device component may be similar to the device component  1070  or  1470  and, for brevity, that description is not repeated here. The housing component  1514  may be configured to have sufficient strength and impact resistance so that the rear wall  1524  maintains structural integrity. 
     In some cases, the housing component  1516  may provide a decorative effect to the housing  1510 , as shown in  FIG.  15 C .  FIG.  15 C  shows an example cross-sectional view of the device  1500  of  FIG.  15 A  along G-G. The cross-section extends through the housing component  1516  and the first housing component  1512   a . In the example of  FIG.  15 C , the housing component  1516  does not extend through a thickness of the housing component  1512   a . For example, the housing component  1516  may form a logo or may cover a recess in the housing component  1512   a . In some examples, the housing component  1516  may be similar in composition, physical properties, electrical properties, and other properties to the housing component  114   b . However, in other examples the housing component  1516  may be able to have a lower glass transition temperature and strength than the housing component  114   b  in order to decrease the cure temperature and/or decrease the cure time. The housing component  1516  may be configured to have sufficient strength and impact resistance so that the front wall  1522  maintains structural integrity. 
     The housing  1510  includes a front wall  1522 , a rear wall  1524 , and four side walls. Sidewalls  1526   a ,  1526   b , and  1526   c  are shown in  FIGS.  15 A and  15 B . In the example of FIGS.  15 A to  15 C, the housing  1510  defines four corners. The corners are shown to be rounded in  FIGS.  15 A and  15 B  but may alternatively be square or have another profile shape (e.g., a squared or angled corner). In additional embodiments, the housing  1510  need not have corners and/or sidewalls. For example, the housing  1510  may have a cylindrical or a lenticular form. 
       FIG.  16    shows a flow chart of an example process  1600  for forming a housing or enclosure including a thermoset composite material. In the example of  FIG.  16   , a housing or a component of the housing is formed from a material other than a thermoset composite material. For example, the housing or housing component(s) may be formed from a metal, a glass, a glass-ceramic, a ceramic, or a combination of these materials. The thermoset composite material may form a housing component when the housing includes multiple components formed from the other material(s). The thermoset composite material may form a component of an enclosure when the housing is formed from a single piece of the other material. 
     The process  1600  includes an operation  1602  of pretreating a surface of the housing or housing component formed from the material other than the thermoset composite material. For example, the surface can be modified by one or more of mechanical texturing, chemical etching, anodization, use of a primer, and the like.  FIG.  2 D  shows an example of an aluminum alloy housing component which has been modified by mechanical texturing, anodization, and use of a primer. 
     In some cases, the surface is pretreated by forming a texture on the surface. Depending on the shape of the housing or housing component, mechanical texturing may include a grinding operation or another form of abrasive treatment such as wet or dry grit blasting. The texture may also be formed at least in part through chemical etching. Chemical etching techniques may involve using a suitable acid or base (e.g., a hydrofluoric acid-based etchant) to remove portions of the glass cover member. The chemical etching may occur in the liquid phase or in a gas phase. Etching techniques also include reactive ion etching, which may use a mixture of a fluorine containing compound such as CH 4 , CHF 3 , SF 6  and the like in a gas such as argon or xenon. 
     A texture may also be formed on the surface due to forming an anodization layer on the surface. When the housing or housing component is formed from a metal material, electrochemical oxidation of the metal material can produce an anodization layer formed from a metal oxide. In some cases, the anodization layer is formed during a phosphoric acid anodizing (PAA) process. The anodization layer is typically thicker than a native oxide layer formed on the metal. For example, the anodization layer may have an average thickness from about 250 nm to about 2 microns or from about 500 nm to about 1.25 microns. In some cases, the anodization layer may be porous. For example, the pores may have an average diameter from about 10 nm to about 100 nm or from about 25 nm to about 75 nm. These pores may contribute to the surface texture. 
     Alternately or additionally, the surface may be pretreated using a primer. In some cases, the primer may include a coupling agent. The coupling agent may be configured to interact with both the thermoset composite material and the surface of the housing or housing component. For example, the coupling agent may interact with a metal oxide formed on the surface such a native oxide layer, an anodization layer, or a sol-gel coating. The coupling agent may also interact with glass, glass-ceramic, and oxide ceramic housing components. In some cases, the coupling agent may be silane-based. For example, the coupling agent may be derived from an alkoxy silane such as a dialkoxy or trialkoxy silane. The alkoxy silane may also include a functional group capable of interacting with one or more components of the polymerizable mixture. For example, the alkoxy silane may include an epoxy group when the thermoset composite material is epoxy-based. When the interface region includes a porous anodization layer, the coupling agent may enter the pores of the anodization layer. 
     In additional examples, the interface region may include a primer other than a silane-based coupling agent. For example, the primer may be derived from a polymerizable mixture different from that used to form the thermoset composite material. In some cases, an epoxy-based primer may be used for both epoxy-based and polyurethane-based thermoset composite materials. When the interface region includes a porous anodization layer, the primer may enter the pores of the anodization layer. 
     The process  1600  also includes an operation  1604  of dispensing a polymerizable mixture onto the surface of the housing or housing component. In some cases, the housing defines an opening and the polymerizable mixture is introduced into the opening. In additional cases, a gap is formed between two housing components and the polymerizable mixture is introduced into the gap. The polymerizable mixture is typically in liquid form and operation  1604  may be a liquid molding technique or a liquid/wet compression molding technique. 
     Surfaces of the housing defining the opening or surfaces of the housing components defining the gap form at least part of a mold for the polymerizable mixture (e.g., the sides of the mold). In some cases, the opening or gap extends through the thickness of the housing or housing component. One or more mold components may be used to provide additional parts of the mold (e.g., a bottom of the mold) in such cases or when it is desired to close the mold (e.g., to apply pressure). In some embodiments one or more of the additional components of the mold may be textured. In additional cases, the opening does not extend completely through the thickness of the housing or housing component as shown in  FIG.  17 A . No additional mold components are required as the housing component forms both the sides and the bottom of the mold. 
     The polymerizable mixture typically includes a pre-polymer of the thermoset polymer. For example, a polymerizable mixture for forming an epoxy-based thermoset may include an epoxy pre-polymer molecule having two or more epoxide functional groups and a polymerizable mixture for forming a polyurethane-based thermoset may include polyurethane pre-polymer having two or more isocyanate functional groups. The polymerizable mixture typically includes a curing agent. Polymerizable mixtures suitable for forming the thermoset composite materials described herein further comprise a reinforcement material such as nano-sized silica or ceramic particles. The polymerizable mixture may further include pigments as well as other additives. A more detailed description of components of polymerizable mixtures is provided below. 
     An epoxy-based thermoset may be formed by reacting an epoxy pre-polymer molecule having two or more epoxide functional groups with a curing agent. An epoxy-based thermoset may also be referred to herein simply as a cross-linked epoxy polymer or matrix. Reference to an epoxy pre-polymer molecule herein may also refer to multiple epoxy-prepolymer molecules of the same type or of different types. Examples of epoxy pre-polymers include, but are not limited to, bisphenol-based pre-polymers (e.g., bisphenol A diglycidal ether, abbreviated as BADGE or DGEBA), aliphatic epoxy pre-polymers such as cycloaliphatic epoxy pre-polymers, novolac-based pre-polymers, and glycidyalamine pre-polymers (e.g., N,N,O-triglycidylamino-4-phenol (TGAP) or N,N,N′,N′-tetraglycidyl diamino-4-4′-diphenylmethane (TGDDM)). In some cases, fluorinated epoxy pre-polymers may be used. Examples of curing agents include, but are not limited to, polyfunctional primary amines, anhydrides, phenols, and the like. 
     A polyurethane-based thermoset may be formed by reacting a polyurethane pre-polymer having two or more icocyanate functional groups with a curing agent. A polyurethane-based thermoset polymer may also be referred to herein simply as a cross-linked polyurethane polymer or matrix. Reference to a polyurethane pre-polymer molecule herein may also refer to multiple epoxy-pre-polymer molecules of the same type or of different types. The polyurethane pre-polymer may be formed by reacting a polyol with a diisocyante. Examples of diisocyanates include aromatic and aliphatic diisocyanates. Examples of polyols include, but are not limited to, polyether polyols, polyester polyols, polycaprolactone polyols and polycarbonate polyols. Examples of curing agents include, but are not limited to, hydroxyl functional curing agents and amine functional curing agents (e.g., aromatic diamines). 
     In some embodiments, the polymerizable mixture includes nano-sized silica particles. For example, the nano-sized silica particles may have a size (e.g., an average diameter) from 10 nm to 100 nm or from 15 nm to 50 nm. The thermoset composite component may include from 10 wt % to 50 wt % of the silica particles. In some cases, nano-sized ceramic particles, such as nano-sized oxide particles, may alternately or additionally be included in the polymerizable mixture. These particles may include, but are not limited to, zirconia, alumina, and/or titanium dioxide particles. However, some of these materials may have a greater dielectric constant than silica and may be less suitable when a substantially RF transparent component is desired. In additional embodiments, at least some of particles included in the mixture may have a larger size, such as greater than 100 nm and less than 20 microns (micrometers), greater than 100 nm and less than 10 microns, greater than 100 nm and less than 5 microns, and greater than 100 nm and less than 1 micron. In some cases, the particle size is an average particle size. 
     In some cases, the polymerizable mixture includes one or more pigments which help to impart a durable color to the thermoset composite component. In some cases, particles of the pigment may be micro-sized or nano-sized. As examples, the pigment particles may have a size less than 20 microns, less than 10 microns, less than 5 microns, less than 1 micron, from 10 nm to 100 nm, from 50 nm to 500 nm, from 500 micron to 5 microns, or from 5 microns to 20 microns. In some cases, the pigment may include an inorganic or carbon pigment, such as titanium dioxide, carbon black, iron oxide, sodium aluminum silicate, and combinations thereof. When the thermoset composite material is used to electrically isolate electrically conductive housing components from each other, the carbon black may have a low conductivity and/or may be included in amounts which do not render the thermoset composite material electrically conductive. In additional cases, the pigment is an organic pigment such as phthalocyanine, benzimidazolone, diarylide, diaszopryazolone, quinacridone, and the like. The pigment loading may be from about 1 wt % to about 5 wt %, from about 2 wt % to about 10 wt %, or from about 5 wt % to about 10 wt %. In some cases, the pigments may be dispersed in a carrier vehicle prior to being added to the polymerizable mixture. 
     The process  1600  also includes an operation  1606  of curing the polymerizable mixture to form the thermoset composite material. Operation  1606  produces an assembly of the thermoset composite material and the housing or housing component(s) formed from a material other than the thermoset composite material. For brevity, this assembly may also be referred to herein as a housing assembly. For example, the polymerizable mixture may be heated to cure the polymerizable mixture and form the crosslinked thermoset composite material. The polymerizable mixture may be heated to a temperature above the desired glass transition temperature. In some cases, the curing temperature may be from about 100° C. to about 150° C. Following operation  1606 , the thermoset composite material is typically bonded to the housing or housing component(s) formed from a material other than the thermoset composite material. In some cases, the bonding between the thermoset composite material and the other material includes adhesive bonding between the thermoset composite material and the other material and/or a component of the interface region such as an anodization layer, a primer, and so forth. For example, the adhesive bonding may include chemical interactions, physical interactions, or both. 
     The process  1600  also includes an operation  1608  of co-machining the housing assembly. The operation  1608  typically involves machining both the thermoset composite material and adjoining portions of the housing or the housing component(s) formed from a material other than the thermoset composite material. Operation  1608  may include one or more machining operations, such as a rough machining operation and a fine machining operation. Operation  1608  may involve removing material from one or both of the interior and the exterior surfaces of the housing assembly. For example, the interior surface of the housing assembly shown in  FIG.  17 A  may be machined to arrive at the housing assembly shown in  FIG.  17 B . In some cases, the housing assembly may be heated between the rough machining operation and the fine machining operation. For example, when the housing assembly is to undergo an anodization process and/or a physical vapor deposition process, the housing assembly may be heated to a temperature similar to the temperature that the housing assembly will experience during the anodization process and/or the physical vapor deposition process. 
     The process  1600  also includes an operation  1610  of texturing the housing assembly of the thermoset composite material and the housing components formed from the material other than the thermoset composite material. In some cases, the housing assembly may be given a smooth or polished texture. In additional cases, the housing assembly may be given a rougher texture, such as a sand-blasted texture. In some cases, the operation  1610  may be optional. 
     The process  1600  also includes an operation  1612  of anodizing the housing assembly. The operation  1612  may form an anodization layer on the exterior surface of the housing or housing components formed at least in part from a metal material. In some cases, the anodization layer formed during the operation  1612  may be thicker than an anodization layer formed during the operation  1602 . For example, the anodization layer formed during the operation  1610  may be at least twice the thickness of the anodization layer formed during the operation  1602 . The anodization layer formed on different metal components may be the same or may be different. If desired, the anodized layer formed during the operation  1612  may be dyed and sealed to impart a desired color to the housing or housing components. As an alternative to operation  1612 , a desired color may be imparted to the housing or housing component using a physical vapor deposition process to deposit a coating on the housing assembly. In some cases, the operation  1612  may be optional, such as for glass, glass-ceramic, and ceramic housing components. 
     The process  1600  also includes an operation  1614  of polishing the thermoset composite material of the housing assembly. In particular, a surface of the thermoset composite material defining an exterior surface of the assembly may be polished to remove small amounts of discoloration that may occur in operation  1612 . In some cases, the operation  1614  may be optional. 
       FIGS.  17 A and  17 B  show examples of a housing assembly at different stages in the operation of  FIG.  16   .  FIG.  17 A  shows an example of a cross-sectional view of a housing assembly  1710   a  after the operation  1606  of curing the polymerizable mixture to form the thermoset composite material. In  FIG.  17 A , the housing assembly  1710   a  includes a thermoset composite material  1714   a  cured in a recess  1711  formed in a housing component  1712   a . The back of the recess forms the back side of the mold, so no additional molding component is needed to form the back side of the mold. This configuration can be useful when the interior and/or exterior surfaces of the housing component(s) such as  1712   a  define a curved surface. In the example of  FIG.  17 A , the interior surface  1707   a  defines a concave curve and the exterior surface  1706   a  defines a convex curve in the plane depicted. The housing component  1712   a  is formed of a material other than the thermoset composite material and in some cases may be formed of a metal material or any of the other materials described with respect to  FIGS.  1 A and  1 B . 
       FIG.  17 B  shows an example of a cross-sectional view of a housing assembly  1710   b  after an operation  1608  of co-machining the housing assembly  1710   a  of  FIG.  17 A . The operation  1608  removes material from at least the interior surface  1707   a  of the housing component  1712   a  to form the housing component  1712   b . Following the operation  1608  the thermoset composite material  1714   b  extends from the exterior surface  1706   b  to the interior surface  1707   b  of the housing assembly  1710   b . The operation  1608  may further remove material from the exterior surface  1706   a  of the housing component  1712   a.    
       FIG.  18    shows a block diagram of a sample electronic device that can incorporate a component comprising a thermoset composite material as described herein, such as a housing component comprising a thermoset composite material. The schematic representation depicted in  FIG.  18    may correspond to components of the devices depicted in  FIGS.  1 A to  17 B  as described above. However,  FIG.  18    may also more generally represent other types of electronic devices with components comprising a thermoset composite material as described herein. 
     In embodiments, an electronic device  1800  may include sensors  1820  to provide information regarding configuration and/or orientation of the electronic device in order to control the output of the display. For example, a portion of the display  1808  may be turned off, disabled, or put in a low energy state when all or part of the viewable area of the display  1808  is blocked or substantially obscured. As another example, the display  1808  may be adapted to rotate the display of graphical output based on changes in orientation of the device  1800  (e.g., 90 degrees or 180 degrees) in response to the device  1800  being rotated. 
     The electronic device  1800  also includes a processor  1806  operably connected with a computer-readable memory  1802 . The processor  1806  may be operatively connected to the memory  1802  component via an electronic bus or bridge. The processor  1806  may be implemented as one or more computer processors or microcontrollers configured to perform operations in response to computer-readable instructions. The processor  1806  may include a central processing unit (CPU) of the device  1800 . Additionally, and/or alternatively, the processor  1806  may include other electronic circuitry within the device  1800  including application specific integrated chips (ASIC) and other microcontroller devices. The processor  1806  may be configured to perform functionality described in the examples above. 
     The memory  1802  may include a variety of types of non-transitory computer-readable storage media, including, for example, read access memory (RAM), read-only memory (ROM), erasable programmable memory (e.g., EPROM and EEPROM), or flash memory. The memory  1802  is configured to store computer-readable instructions, sensor values, and other persistent software elements. 
     The electronic device  1800  may include control circuitry  1810 . The control circuitry  1810  may be implemented in a single control unit and not necessarily as distinct electrical circuit elements. As used herein, “control unit” will be used synonymously with “control circuitry.” The control circuitry  1810  may receive signals from the processor  1806  or from other elements of the electronic device  1800 . 
     As shown in  FIG.  18   , the electronic device  1800  includes a battery  1814  that is configured to provide electrical power to the components of the electronic device  1800 . The battery  1814  may include one or more power storage cells that are linked together to provide an internal supply of electrical power. The battery  1814  may be operatively coupled to power management circuitry that is configured to provide appropriate voltage and power levels for individual components or groups of components within the electronic device  1800 . The battery  1814 , via power management circuitry, may be configured to receive power from an external source, such as an alternating current power outlet. The battery  1814  may store received power so that the electronic device  1800  may operate without connection to an external power source for an extended period of time, which may range from several hours to several days. 
     In some embodiments, the electronic device  1800  includes one or more input devices  1818 . The input device  1818  is a device that is configured to receive input from a user or the environment. The input device  1818  may include, for example, a push button, a touch-activated button, a capacitive touch sensor, a touch screen (e.g., a touch-sensitive display or a force-sensitive display), a capacitive touch button, dial, crown, or the like. In some embodiments, the input device  1818  may provide a dedicated or primary function, including, for example, a power button, volume buttons, home buttons, scroll wheels, and camera buttons. 
     The device  1800  may also include one or more sensors or sensor modules  1820 , such as a force sensor, a capacitive sensor, an accelerometer, a barometer, a gyroscope, a proximity sensor, a light sensor, or the like. In some cases, the device  1800  includes a sensor array (also referred to as a sensing array) which includes multiple sensors  1820 . For example, a sensor array associated with a protruding feature of a cover member may include an ambient light sensor, a Lidar sensor, and a microphone. As previously discussed with respect to  FIG.  1 B , one or more camera modules may also be associated with the protruding feature. The sensors  1820  may be operably coupled to processing circuitry. In some embodiments, the sensors  1820  may detect deformation and/or changes in configuration of the electronic device and be operably coupled to processing circuitry that controls the display based on the sensor signals. In some implementations, output from the sensors  1820  is used to reconfigure the display output to correspond to an orientation or folded/unfolded configuration or state of the device. Example sensors  1820  for this purpose include accelerometers, gyroscopes, magnetometers, and other similar types of position/orientation sensing devices. In addition, the sensors  1820  may include a microphone, acoustic sensor, light sensor (including ambient light, infrared (IR) light, ultraviolet (UV) light, optical facial recognition sensor, a depth measuring sensor (e.g., a time of flight sensor), a health monitoring sensor (e.g., an electrocardiogram (erg) sensor, a heart rate sensor, a photoplethysmogram (ppg) sensor, a pulse oximeter, a biometric sensor (e.g., a fingerprint sensor), or other types of sensing device. 
     In some embodiments, the electronic device  1800  includes one or more output devices  1804  configured to provide output to a user. The output device  1804  may include display  1808  that renders visual information generated by the processor  1806 . The output device  1804  may also include one or more speakers to provide audio output. The output device  1804  may also include one or more haptic devices that are configured to produce a haptic or tactile output along an exterior surface of the device  1800 . 
     The display  1808  may include a liquid-crystal display (LCD), a light-emitting diode (LED) display, an LED-backlit LCD display, an organic light-emitting diode (OLED) display, an active layer organic light-emitting diode (AMOLED) display, an organic electroluminescent (EL) display, an electrophoretic ink display, or the like. If the display  1808  is a liquid-crystal display or an electrophoretic ink display, the display  1808  may also include a backlight component that can be controlled to provide variable levels of display brightness. If the display  1808  is an organic light-emitting diode or an organic electroluminescent-type display, the brightness of the display  1808  may be controlled by modifying the electrical signals that are provided to display elements. In addition, information regarding configuration and/or orientation of the electronic device may be used to control the output of the display as described with respect to input devices  1818 . In some cases, the display is integrated with a touch and/or force sensor in order to detect touches and/or forces applied along an exterior surface of the device  1800 . 
     The electronic device  1800  may also include a communication port  1812  that is configured to transmit and/or receive signals or electrical communication from an external or separate device. The communication port  1812  may be configured to couple to an external device via a cable, adaptor, or other type of electrical connector. In some embodiments, the communication port  1812  may be used to couple the electronic device  1800  to a host computer. 
     The electronic device  1800  may also include at least one accessory  1816 , such as a camera, a flash for the camera, or other such device. The camera may be part of a camera assembly that may be connected to other parts of the electronic device  1800  such as the control circuitry  1810 . 
     As used herein, the terms “about,” “approximately,” “substantially,” “similar,” and the like are used to account for relatively small variations, such as a variation of +/−10%, +/−5%, +/−2%, or +/−1%. In addition, use of the term “about” in reference to the endpoint of a range may signify a variation of +/−10%, +/−5%, +/−2%, or +/−1% of the endpoint value. In addition, disclosure of a range in which at least one endpoint is described as being “about” a specified value includes disclosure of the range in which the endpoint is equal to the specified value. 
     As used herein, the phrase “at least one of” preceding a series of items, with the term “and” or “or” to separate any of the items, modifies the list as a whole, rather than each member of the list. The phrase “at least one of” does not require selection of at least one of each item listed; rather, the phrase allows a meaning that includes at a minimum one of any of the items, and/or at a minimum one of any combination of the items, and/or at a minimum one of each of the items. By way of example, the phrases “at least one of A, B, and C” or “at least one of A, B, or C” each refer to only A, only B, or only C; any combination of A, B, and C; and/or one or more of each of A, B, and C. Similarly, it may be appreciated that an order of elements presented for a conjunctive or disjunctive list provided herein should not be construed as limiting the disclosure to only that order provided. 
     The following discussion applies to the electronic devices described herein to the extent that these devices may be used to obtain personally identifiable information data. It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not intended 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: 20210908
Publication Date: 20231010
Grant Date: 20231010
Priority Date: 20200916
Inventors: BLOOM, DANIEL R.
WOJESKI, CHELSEA E.
SIAHAAN, EDWARD
MORRIS, NATHAN
HALEY, RYAN S.
LI, TIAN SHI
RISTOSKI, TONI
Assignee: APPLE INC
CPC Classifications: [{"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/22", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0247", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B1/3827", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04B1/3827", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/163", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1698", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04R60/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "G04G21/025", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/273", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 77774737