PATENT DOCUMENT

Publication Number: US-9941581-B2
Application Number: US-201514945335-A
Country: US
Kind Code: B2

Title: Antenna window and antenna pattern for electronic devices and methods of manufacturing the same

Abstract:
A housing for an electronic device, including an aluminum layer enclosing a volume that includes a radio-frequency (RF) antenna is provided. The housing includes a window aligned with the RF antenna; the window including a non-conductive material filling a cavity in the aluminum layer; and a thin aluminum oxide layer adjacent to the aluminum layer and to the non-conductive material; wherein the non-conductive material and the thin aluminum oxide layer form an RF-transparent path through the window. A housing for an electronic device including an integrated RF-antenna is also provided. A method of manufacturing a housing for an electronic device as described above is provided.

Claims:
What is claimed is: 
     
       1. A housing for an electronic device, comprising:
 a metal layer; 
 a first and a second gap formed through a thickness of the metal layer and arranged to form an electrically isolated segment of the metal layer, wherein the electrically isolated segment forms a radio frequency (RF) antenna;
 a non-conductive material filling the first and the second gaps in the metal layer; and 
 a metal oxide layer formed on an exterior surface of the metal layer and extending across the first and the second gaps and the electrically isolated segment, wherein the metal oxide layer forms an RF-transparent window. 
 
 
     
     
       2. The electronic device of  claim 1 , wherein the non-conductive material is a metal oxide. 
     
     
       3. The electronic device of  claim 1 , wherein the metal layer is aluminum. 
     
     
       4. The electronic device of  claim 1 , wherein the non-conductive material comprises a polymer. 
     
     
       5. The electronic device of  claim 1 , further comprising a third gap formed through the thickness of the metal layer. 
     
     
       6. The electronic device of  claim 1 , wherein the metal layer comprises aluminum and the metal oxide layer comprises aluminum oxide. 
     
     
       7. A method of manufacturing a housing for an electronic device, the method comprising:
 forming a metal layer; 
 forming a first and a second gap through a thickness of the metal layer to isolate a segment of the metal layer; 
 filling the first and second gaps with a non-conductive material; and 
 forming a metal oxide layer on the metal layer, wherein the metal oxide layer extends across the first and the second gaps and the segment. 
 
     
     
       8. The method of  claim 7 , wherein the non-conductive material is a metal oxide. 
     
     
       9. The method of  claim 7 , wherein the metal oxide layer is formed before the first and second gaps. 
     
     
       10. The method of  claim 7 , wherein forming the first and the second gaps is performed by converting portions of the metal layer to a metal oxide. 
     
     
       11. The method of  claim 10 , wherein forming the first and the second gaps includes masking a portion of an interior surface of the metal layer and performing a Plasma Electrolytic Oxidation (PEO) at an unmasked portion of an interior surface of the metal layer. 
     
     
       12. The method of  claim 7 , wherein the filling includes using a material selected from the group consisting of a plastic, a thermosetting polymer, and a resin. 
     
     
       13. The method of  claim 7 , forming the first and the second gaps includes machining the metal layer, etching away the metal layer, or both. 
     
     
       14. The method of  claim 7 , wherein forming the first and the second gaps includes forming micro-perforations in an interior side of the metal layer to establish thin wall sections that allow substantially all of the metal layer at the thin wall sections to be anodized. 
     
     
       15. The method of  claim 7 , further comprising:
 forming a third gap in the metal layer. 
 
     
     
       16. The method of  claim 15 , wherein one or more RF antennas are formed in the metal layer. 
     
     
       17. The method of  claim 7 , wherein the metal oxide layer is formed by first depositing an aluminum layer on a surface of the housing by performing a process selected from the group consisting of physical vapor deposition, chemical vapor deposition, ion vapor deposition, cathodic arc deposition, and plasma spray deposition.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/973,939, filed Aug. 22, 2013, entitled ANTENNA WINDOW AND ANTENNA PATTERN FOR ELECTRONIC DEVICES AND METHODS OF MANUFACTURING THE SAME, which claims the benefit of U.S. Provisional Patent Application No. 61/832,760, filed Jun. 7, 2013, entitled ANTENNA WINDOW AND ANTENNA PATTERN FOR ELECTRONIC DEVICES AND METHODS OF MANUFACTURING THE SAME, both of which are incorporated by reference herein in their entireties. 
    
    
     FIELD OF THE DESCRIBED EMBODIMENTS 
     The described embodiments relate generally to housings for electronic devices adapted to include radio-frequency (RF) antennas. More particularly, embodiments disclosed herein relate to metallic housings for portable electronic devices adapted to include radio-frequency antennas. 
     BACKGROUND 
     Antenna architecture is an integral part of a consumer electronics product. Housings and structural components are often made from conductive metal, which can serve as a ground for an antenna. However, antennas require nonconductive regions or other isolation to provide a good radiation pattern and signal strength. To solve this problem conventional designs include a plastic antenna window or a plastic split in a housing to separate the conductive metal. However, this approach breaks the consistent visual profile of the device, deteriorating the cosmetic appeal of the metal surface. Also, replacing metallic portions of the housing with softer materials weakens the underlying metal and uses device volume to fasten the parts together. 
     Therefore, what is desired is a housing for an electronic device that integrates antenna designs in a manner that is visually consistent with the cosmetic appeal of the device and that provides structural support for the device and functional support for the antenna. 
     SUMMARY OF THE DESCRIBED EMBODIMENTS 
     In a first embodiment, a housing for an electronic device is provided. The housing may include an aluminum layer enclosing a volume that includes a radio-frequency (RF) antenna, the aluminum layer having a window aligned with the RF antenna. The window includes a non-conductive material filling a gap in the aluminum layer and a thin aluminum oxide layer adjacent to the aluminum layer and to the non-conductive material. The non-conductive material and the thin aluminum oxide layer form an RF-transparent path to allow transmission of substantially all RF radiation through the window. 
     In a second embodiment, a housing for an electronic device is provided. The housing may include an aluminum layer enclosing a number of electronic circuits. The housing also may also include an oxide layer on an exterior surface of the aluminum layer. The housing may additionally include one or more radio-frequency (RF) antennas. The one or more RF antennas includes an electrically conductive path including a first segment and a second segment. The one or more RF antennas also includes a non-conductive material adjacent to the conductive path, the non-conductive material electrically insulating the first segment of the electrically conductive path from the second segment of the electrically conductive path. The one or more RF antenna additionally includes an RF-transparent material layer adjacent to the hard material layer and to the electrically conductive path. At least one of the first segment and the second segment is part of the aluminum layer. 
     In a third embodiment, a method of manufacturing a housing for an electronic device is provided. The method may include converting an aluminum layer in the housing to an exterior aluminum oxide layer. The method may also include removing the aluminum layer adjacent to the aluminum oxide layer to form a gap in a window portion of the housing. The method may additionally include filling the gap in the window portion with a non-conductive material. Accordingly, the gap allows transmission of substantially all RF radiation through the window portion. 
     In yet another embodiment, a method of forming a radio-frequency (RF) transparent window in an aluminum housing for an electronic device is provided. The method may include inserting an RF transparent material into a window opening in the aluminum housing. The method may also include forming a thin aluminum layer on an exterior surface of the aluminum housing and the RF transparent material. The method may further include anodizing the thin aluminum layer to form an aluminum oxide layer so that the aluminum oxide layer is adjacent to the RF transparent material in the window opening, allowing transmission of substantially all RF radiation through the window. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The described embodiments may be better understood by reference to the following description and the accompanying drawings. Additionally, advantages of the described embodiments may be better understood by reference to the following description and accompanying drawings. These drawings do not limit any changes in form and detail that may be made to the described embodiments. Any such changes do not depart from the spirit and scope of the described embodiments. 
         FIGS. 1A-1C  illustrate a portable electronic device, according to some embodiments. 
         FIGS. 2A-2C  illustrate steps in a method of forming a housing for an electronic device including a Radio-Frequency (RF) antenna, according to some embodiments. 
         FIGS. 3A-3C  illustrate steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 4A  illustrates a partial plan view of a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIGS. 4B-4D  illustrate steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIGS. 5A-5B  illustrate steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIGS. 6A-6C  illustrate a portable electronic device, according to some embodiments. 
         FIGS. 7A-7D  illustrate steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIGS. 8A-8G  illustrate steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 9  illustrates a cross-sectional view of a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 10  illustrates a cross-sectional view of a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 11A-11B  illustrate steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 12  illustrates a flow chart with steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 13  illustrates a flow chart with steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
         FIG. 14  illustrates a flow chart with steps in a method of forming a housing for an electronic device including an RF antenna, according to some embodiments. 
     
    
    
     In the figures, elements referred to with the same or similar reference numerals include the same or similar structure, use, or procedure, as described in the first instance of occurrence of the reference numeral. 
     DETAILED DESCRIPTION OF SELECTED EMBODIMENTS 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data, which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     Electronic device housings consistent with the present disclosure include a hard, cosmetic anodized surface of aluminum. The anodized surface is nonconductive and thus is transparent to radio-frequency (RF) electronic radiation. In some embodiments, the anodized surface may have a thickness on the order of 10 microns (1 micron=1 μm=10 −6  m). By adjusting the anodization parameters the anodization depth can be made to have a thickness of over 100 microns. A number of design techniques (outlined in the attachment) can be used to create a continuous, anodized, cosmetic aluminum surface that is selectively conductive in certain portions and non-conductive in other portions. This allows an antenna window or even an antenna to be patterned directly into the housing. Such electronic device housing improves product cosmetics, and reduces the size of the device. 
     Antenna windows in aluminum enclosures are challenging. Prior solutions include splits in housings and plastic covered antenna windows. Our proposed solution is to use aluminum oxide as the antenna window. Aluminum oxide is non-conductive and transparent to RF. Aluminum oxide is created during the process of anodization. The thickness can be nominally up to 100 um thick or higher by careful adjustment of the anodization parameters. The process, as outlined in the attached, includes anodization of the exterior housing and then etching away on the interior of the housing antenna windows at desired locations for antenna windows, followed by filling in the etched portions with plastic, paint, or other suitable material to maintain structural integrity. The aluminum oxide can be substantially clear or transparent, allowing the filling material to show through. The resulting housing is cosmetically pleasing and without cracks or apparent plastic portions. 
     Accordingly, embodiments consistent with the present disclosure provide a housing for an electronic device integrating antenna designs in a manner that is visually consistent with the cosmetic appeal of the device. In some embodiments, an electronic device housing provides structural support for the device and functional support for the antenna integrated in the device. In some embodiments, a housing for an electronic device includes a window for an antenna, the window providing RF-transparency for the antenna signals while maintaining a consistent visual appeal for the device. Also, the RF-transparent window maintains a structural support for the housing. 
       FIG. 1A  illustrates a plan view of a front face in a portable electronic device  10 , according to some embodiments. Portable electronic device  10  includes a housing  150  holding a display cover  20  and having a sensor aperture  30 . Sensor aperture  30  may Portable electronic device  10  also includes at least an RF antenna  50  which may be integrated into housing  150 . In some embodiments RF antenna  50  may be in the interior side of housing  150 . In that regard, portable electronic device  10  may include multiple RF antennas, some of which may be integrated into housing  150 , and others may be included in the interior side of housing  150 . While RF antenna  50  in  FIG. 1A  is shown as a coil wrapping around display cover  20 , other configurations are possible. Housing  150  may include an RF-transparent layer  100  over a hard material substrate  110 . In some embodiments, RF-transparent layer  100  may be an oxide layer formed from hard material substrate  110 . For example, hard material layer  110  may include an aluminum layer and RF-transparent layer  100  may be aluminum oxide formed from converting a portion of the aluminum layer. Accordingly, RF-transparent layer may be an exterior layer of housing  150 , and hard material layer  110  may be an interior layer of housing  150 . 
       FIG. 1B  illustrates a cross-sectional view of portable electronic device  10 , according to some embodiments. The cross-section in  FIG. 1B  is taken along segment A-A′ (cf.  FIG. 1A ).  FIG. 1B  illustrates a configuration where RF antenna  50  is integrated into housing  150 . While RF antenna  50  includes a conductive portion, the antenna is configured to include portions of RF-transparent layer  120  separating different segments of RF antenna  50 . As mentioned above, in some embodiments hard material substrate  110  includes a metal. Thus, hard material layer  110  provides structural support to the electronic device, and also a ground connection for RF antenna  50 , in some embodiments. RF-transparent layer  100  may include an electrically resistive material (e.g., aluminum oxide) effectively isolating segments of RF antenna  50  from each other and from other conductive portions of housing  150  (e.g., aluminum layer  110 ).  FIG. 1C  illustrates a plan view of a back face in portable electronic device  10 , according to some embodiments. Accordingly, in some embodiments a cross section of housing  150  as shown in  FIG. 1B  may include no conductive material, such as aluminum (e.g., layer  110 ) in certain portions of housing  150  (e.g., layers  120 ). Such embodiments enable antenna  50  to be integrated within housing  150  as the non-conductive material in layer  120  is adjacent to the conductive path in antenna  50 . The non-conductive material in layer  120  electrically insulates a first segment in antenna  50  from a second segment in the conductive path of antenna  50 .  FIG. 1C  illustrates a sensor aperture  40  which may be configured to allow a camera to receive visible light from outside of housing  150 . In some embodiments aperture  40  may be configured to allow an audio device to transmit or receive acoustic signals to and from outside housing  150 . 
       FIGS. 2A-2C  illustrate steps in a method of forming housing  150  for electronic device  10  including Radio-Frequency (RF) antenna  50 , according to some embodiments.  FIG. 2A  illustrates a step of placing a non-conductive material  211  in a hard material layer  201  forming housing  150 . Hard material layer  201  may include an electrically conductive material such as a metal (e.g., aluminum). Non-conductive material  211  may be a plastic, a ceramic material, or glass. In some embodiments, non-conductive material  211  may include a thermosetting polymer, an epoxy, or some other glue including a curable resin. The step illustrated in  FIG. 2A  may include forming a gap in hard material layer  201  and molding plastic material  211  inside the gap. Accordingly, the gap may have the profile of an antenna window, and be formed in a portion of housing  150  proximate or adjacent to RF antenna  50 .  FIG. 2B  illustrates a step of coating a thin layer of hard material  205  on a side of housing  150  overlapping layers  201  and non-conductive material  211 . Layer  205  may include the same material as layer  201 . For example, if layer  201  is aluminum, layer  205  may be formed by coating a thin aluminum layer on the side of housing  150 , as illustrated in  FIG. 2B . The step in  FIG. 2B  may include Physical Vapor Deposition (PVD) of a metal to form layer  205 . Examples of PVD may include sputtering and other procedures known in the art. Accordingly, the step in  FIG. 2B  may include metallization of a ceramics substrate by steps including ion vapor deposition, chemical vapor deposition (CVD), cathodic arc deposition, plasma spray, and others known in the art.  FIG. 2C  illustrates a step of oxidizing the thin layer of hard material  205  to form a thin RF-transparent layer  221 . In some embodiments, thin RF-transparent layer  211  includes an aluminum oxide layer formed by anodization of thin aluminum layer  205 . RF-transparent layer  211  can include metal, just not solid bulk metal or alloy that will block RF transmission. As a result of the steps illustrates in  FIGS. 2A-2C , a portion of housing  150  has a cross-section such that an RF-transparent path is formed from an exterior side of housing  150  to an interior side of housing  150 . 
       FIGS. 3A-3C  illustrate steps in a method of forming housing  150  for electronic device  10  including antenna  50 , according to some embodiments.  FIG. 3A  illustrates a step providing a layer of hard material  201  (cf.  FIGS. 2A-2C , above).  FIG. 3B  illustrates a step of forming RF-transparent layer  221  adjacent to layer  201  (cf.  FIG. 2C ). Accordingly, the step in  FIG. 3B  may include anodizing an aluminum layer  201  to form aluminum oxide layer  221  with a pre-selected thickness. In some embodiments, the thickness of aluminum oxide layer  221  may be about 12 μm. Such an aluminum oxide layer may result from ‘consuming’ an approximately 5 μm to 6 μm aluminum layer through anodization.  FIG. 3C  illustrates a step of forming a non-conductive layer  231  in a portion of hard material layer  201 . The step in  FIG. 3C  may include a ‘hard’ anodization process to form a thick aluminum oxide layer  231  having a similar thickness as hard material layer  201 . For example, in embodiments where hard material layer  201  includes aluminum, the step in  FIG. 3C  may include using Plasma Electrolytic Oxidation (PEO) to produce a thick layer of alumina (aluminum oxide in crystalline form), also known as sapphire, as non-conductive layer  231 . In some embodiments, the step in  FIG. 3C  may include use of a mask overlapping portions of hard material layer  201  so that layer  231  separates portions of hard material layer  201 , prior to anodizing layer  201 . Accordingly, layer  231  may be thicker than layer  221 . In some embodiments, layer  231  may be up to 50 μm thick, or even more. Some embodiments consistent with the present disclosure may form a thinner aluminum oxide layer  221  on the exterior portion of housing  150 , and a thicker aluminum oxide layer  231  on the interior portion of housing  150 . Thus, a thinner aluminum oxide layer  221  may be as layer  100  covering all or almost all of the exterior side of housing  150 , and a thicker aluminum oxide layer  231  may cover selected portions of the interior side of housing  150  (e.g., layer  120 , cf.  FIGS. 1A-1C ). 
       FIG. 4A  illustrates a partial plan view of a housing  450  for electronic device  10  including RF antenna  50 , according to some embodiments. Housing  450  may include a honeycomb configuration where islands  451  made of hard material  201  are isolated from one another by channels  421 . Islands  451  may include a conductive material such as aluminum, and channels  421  may include a non-conductive material (e.g., non-conductive material  211 , cf.  FIG. 2C ).  FIG. 4A  illustrates a honeycomb structure having similar hexagonally shaped islands  451  adjacent to one another. The honeycomb structure can provide stiffness to RF antenna  50  and can provide areas that are sufficiently thin so as to be fully anodized to RF transparent material. While this is an exemplary embodiment, one of ordinary skill would recognize that islands  451  may have any shape. Furthermore, islands  451  may have different shape and size from one another. 
       FIGS. 4B-D  illustrate steps in a method of forming housing  450  for electronic device  10  including RF antenna  50 , according to some embodiments.  FIG. 4B  illustrates a step of forming micro perforations  420  in a hard material layer  201  (cf.  FIGS. 2A-2C  and  FIGS. 3A-3C ). Micro perforations  420  can be used to reduce the thickness of hard material layer  201  in areas of micro perforations  420  while maintaining its stiffness. In embodiments where hard material layer  201  includes aluminum, the micro perforations  420  goes through the aluminum and through an aluminum oxide layer adjacent to the aluminum. Micro perforations  420  may be formed by laser machining of aluminum in hard material layer  201 .  FIG. 4C  illustrates a step of forming non-conductive layer  231  from portions of hard material layer  201 . Accordingly, the step in  FIG. 4C  may include selectively anodizing the aluminum in hard material layer  201  to form areas of aluminum oxide, which are RF transparent. In some embodiments, anodizing forms an aluminum oxide layer having a thickness of between about 5 to 300 microns. In particular, aluminum oxide can be formed at micro perforations  420  where the aluminum is very thin. Since the aluminum is thin at micro perforations  420 , these regions can have cross sections that are fully anodized to aluminum oxide, thereby creating areas within RF antenna  50  that are RF transparent. The step in  FIG. 4C  may include using a mask to cover a portion  461  of hard material  201 . Portion  461  may form an island of aluminum, a metal, or some other conducting material surrounded by non-conductive layer  231 .  FIG. 4D  illustrates a step of forming a support layer  471  on a side of housing  150 . Support layer  471  provides structural integrity and stiffness to housing  150 . In some embodiments, support layer  471  may include a fiberglass coating, or a thin layer of glass or plastic. It is desirable that support layer  471  be made of a non-conducting material so as not to compromise the operation of an RF antenna integrated in housing  150 .  FIG. 4D  also illustrates portions  421  and  451  of housing  450  (cf.  FIG. 4A ). 
       FIGS. 5A-5B  illustrate steps in a method of forming housing  450  for electronic device  10  including RF antenna  50 , according to some embodiments.  FIG. 5A  illustrates a step similar to the step illustrated in  FIG. 4B .  FIG. 5B  illustrates a step of forming a non-conductive layer  231  from portions of hard material layer  201 , and forming an RF-transparent layer  221  on a side of housing  150 , overlapping non-conductive layer  231  and portion  461 . 
       FIGS. 6A-6C  illustrate a portable electronic device  10  including an antenna window  60 , according to some embodiments.  FIG. 6A  illustrates a plan view of a front face in portable electronic device  10  including antenna window  60 , according to some embodiments.  FIG. 6A  includes display cover  20  and sensor aperture  30 , as described in detail above (cf.  FIG. 1A ).  FIG. 6B  illustrates a cross-sectional view of portable electronic device  10  including antenna window  60 , according to some embodiments. Antenna window  60  is placed in apportion of housing  150  proximal to RF antenna  50 . In some embodiments antenna window  60  may be adjacent to RF antenna  50 .  FIG. 6C  illustrates a plan view of a back face in portable electronic device  10  including antenna window  60 , according to some embodiments.  FIG. 6C  also includes sensor aperture  40 , as described in detail above (cf.  FIG. 1C ). As mentioned above in reference to  FIGS. 1A-1C , embodiments consistent with the present disclosure may include multiple RF antennas located in different areas in portable electronic device  10 . For example, an RF antenna may be integrated in housing  150  (cf.  FIG. 1A ), and another RF-antenna may be in the interior side of housing  150 , adjacent to antenna window  60  (cf.  FIG. 6B ). 
       FIGS. 7A-7D  illustrate steps in a method of forming housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments.  FIG. 7A  illustrates a step of forming an RF-transparent layer  221  adjacent to a hard material layer  201 . The geometry of the cavity can be in the form of a pocket, trench, or any suitable shape that does not break the plane of layer  221 .  FIG. 7B  illustrates a step of forming a cavity in hard material layer  201 . The step in  FIG. 7B  may include machining the cavity, or etching away a portion of material in layer  201  to form the cavity.  FIG. 7C  illustrates a step of removing a thin residual of material in layer  201  adjacent to layer  221  in the cavity. The cavity can be formed by laser ablation, chemical etch, or other suitable technique as recognized by a person of skill in the art.  FIG. 7D  illustrates a step of filling the cavity in layer  201  with non-conductive material  211 . 
       FIGS. 8A-8G  illustrate steps in a method of forming housing  150  for electronic device  10  including RF antenna  60 , according to some embodiments.  FIG. 8A  illustrates a step similar to the step illustrated in  FIG. 7A .  FIG. 8B  illustrates a step similar to step  7 B illustrated in  FIG. 7B .  FIG. 8C  illustrates a step of forming a masking layer  801  around layers  201  and  221 , including the cavity formed in the step illustrated in  FIG. 8B .  FIG. 8D  illustrates a step of selectively removing masking layer  801  in an area overlapping a residual thickness of material  201  adjacent to layer  221  in the cavity formed in the step illustrated in  FIG. 8B . The step illustrated in  FIG. 8D  may include etching away masking layer  801  in the selected portion.  FIG. 8E  illustrates a step of removing the hard material  201  left unmasked in step  8 D.  FIG. 8F  illustrates a step of removing residual masking layer  801 .  FIG. 8G  illustrates a step of filling the cavity with non-conductive material  211 . 
     Accordingly, in embodiments of housing  150  for electronic device  10  where the hard material layer  110  forming the housing is aluminum, some embodiments of an RF-antenna window may include removing all aluminum material in the window area (cf.  FIGS. 7D and 8E ). Such configuration enhances the RF-transparency of the window, as aluminum layers of even a few nm thick have a non-zero absorbance in the RF frequency spectrum. 
       FIG. 9  illustrates a cross-sectional view of housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments. Accordingly,  FIG. 9  illustrates hard material layer  201 , RF-transparent layer  221 , and non-conductive layer  211  in a gap of layer  201 . Non-conductive layer  211  includes RF antenna  50 . In some embodiments, RF antenna  50  includes a strip of conductive material (e.g., aluminum) adjacent to RF-transparent layer  221 . 
       FIG. 10  illustrates a cross-sectional view of housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments. Accordingly,  FIG. 10  illustrates hard material layer  201 , RF-transparent layer  221 , and non-conductive layer  211  in a gap of layer  201 . Non-conductive layer  211  includes RF antenna  50 . In some embodiments, RF antenna  50  includes a strip of conductive material (e.g., aluminum) embedded within non-conductive layer  211 . 
       FIG. 11A-11B  illustrate steps in a method of forming housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments.  FIG. 11A  illustrates a step of forming a gap in a hard material layer  201 . The step in  FIG. 11A  also includes placing a block including RF-transparent layer  221  adjacent to non-conductive layer  211  in the gap formed in layer  201 .  FIG. 11B  illustrates a step of extending RF-transparent layer  221  across the gap, overlapping hard material layer  201 . 
       FIG. 12  illustrates a flow chart with steps in a method  1200  of forming housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments. Step  1210  includes forming a gap on the housing. The housing may include a hard material layer made of aluminum (e.g., layer  110 , cf.  FIG. 1B ). Accordingly, step  1210  may be as described in detail in relation to  FIG. 2A . Step  1220  includes filling the gap with a non-conductive material. Accordingly, steps  1210  and  1220  may be included in the steps illustrated in detail in relation to  FIG. 2A . Step  1230  includes forming a thin material layer over the gap (cf.  FIG. 2B ). And step  1240  includes oxidizing the thin material layer (cf.  FIG. 2C ). Accordingly, step  1240  may include forming an RF-transparent layer adjacent to a portion of the hard material layer and the non-conductive material filling the gap in the hard material layer. 
       FIG. 13  illustrates a flow chart with steps in a method  1300  of forming housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments. Step  1310  includes forming a first oxidized layer on a first side of a hard material layer. In some embodiments, step  1310  may include anodizing an aluminum layer to form a thin RF-transparent layer on one side (e.g., layer  221 , cf.  FIG. 3B ). Step  1320  includes forming a second oxidized layer on a second side of the hard material layer (e.g., layer  231 , cf.  FIG. 3C ). 
       FIG. 14  illustrates a flow chart with steps in a method  1400  of forming housing  150  for electronic device  10  including RF antenna  50 , according to some embodiments. Step  1410  includes forming an oxidized layer on a hard material layer. In some embodiments, step  1410  may include anodizing an aluminum layer to form a thin RF-transparent layer (e.g., layer  221 , cf.  FIGS. 7A and 8A ). Step  1420  includes forming a gap on the hard material layer on a side opposite to the oxidized layer (cf.  FIGS. 7B and 8B ). Step  1430  includes removing residual material from the hard material layer adjacent to the oxidized layer in the gap (cf.  FIGS. 7C and 8C -F). Step  1440  includes filling the gap with a non-conductive material (cf.  FIGS. 7D and 8G ). 
     Embodiments of antenna windows and methods of manufacturing the same as disclosed herein may also be implemented with other sensors included in electronic device  10 . For example, in some embodiments patch  60  may include a touch sensitive pad configured to receive a touch from the user. The touch sensitive pad may be capacitively coupled to an electronic circuit configured to determine touch position and gesture interpretation. 
     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 specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described 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: 20151118
Publication Date: 20180410
Grant Date: 20180410
Priority Date: 20130607
Inventors: ELY COLIN M.
PREST CHRISTOPHER D.
BROWNING LUCY E.
LYNCH STEPHEN B.
LAAKMANN ERIC S.
NANGERONI PAUL L.
Assignee: APPLE INC
CPC Classifications: [{"code": "C23C28/322", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/322", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/5853", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/42", "inventive": true, "first": true, "tree": "[]"}, {"code": "C23C28/345", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/345", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C16/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C16/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/5853", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/42", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C28/322", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/5853", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/42", "inventive": true, "first": true, "tree": "[]"}, {"code": "C23C28/345", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C14/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/24", "inventive": true, "first": false, "tree": "[]"}, {"code": "C23C16/06", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 52005014