PATENT DOCUMENT

Publication Number: US-9518333-B2
Application Number: US-201414503009-A
Country: US
Kind Code: B2

Title: Assembled integral plastic elements on an anodized mobile device enclosure

Abstract:
Methods and systems for manufacturing composite parts that include anodizable portions and non-anodizable portions such that an interface between the anodizable portions and non-anodizable portions are free of visible defects are described. The non-anodizable portions can be made of anodizable metals such as aluminum or aluminum alloy. The non-anodizable portions are made of material that do not generally form an anodic film, such as plastic, ceramic or glass materials. In particular, the methods described relate to manufacturing methods that are compatible with anodizing processes and avoid defects related to anodizing processes. In particular embodiments, the methods involve avoiding trapping of anodizing chemicals within a gap between an anodizable portion and a non-anodizable portion, which prevents the anodizing chemicals from disrupting the uptake of dye in a post-anodizing dyeing process.

Claims:
What is claimed is: 
     
       1. A method of manufacturing an enclosure that includes a non-anodizable portion coupled with an anodizable portion, the method comprising:
 co-machining a surface of the non-anodizable portion with a surface of the anodizable portion such that the surface of the non-anodizable portion cooperates with the surface of the anodizable portion to form a curved surface; 
 decoupling the non-anodizable portion from the anodizable portion; 
 subsequent to the decoupling, anodizing the anodizable portion, thereby forming an anodic film on the anodizable portion; and 
 securing the non-anodizable portion with the anodizable portion such that the curved surface is reformed. 
 
     
     
       2. The method of  claim 1 , wherein the non-anodizable portion is positioned within a pocket of the anodizable portion. 
     
     
       3. The method of  claim 1 , further comprising dyeing the anodic film. 
     
     
       4. The method of  claim 1 , wherein the curved surface is a spline shaped surface. 
     
     
       5. The method of  claim 1 , further comprising
 applying a first pressure in a first direction to the non-anodizable portion such that the surface of the anodizable portion is in an inset position with respect to the surface of the non-anodizable portion; and 
 applying a second pressure in a second direction opposite the first direction to the non-anodizable portion such that the curved surface is reformed. 
 
     
     
       6. The method of  claim 5 , wherein the second pressure is a vacuum suction pressure. 
     
     
       7. The method of  claim 5 , further comprising:
 prior to applying the second pressure, positioning the enclosure adjacent a datum surface having a shape corresponding to the curved surface of the enclosure, wherein applying the second pressure comprises aligning the surface of the anodizable portion and the surface of the non-anodizable portion with the datum surface. 
 
     
     
       8. The method of  claim 1 , further comprising:
 prior to securing the non-anodizable portion with the anodizable portion, applying an adhesive between the non-anodizable portion and the anodizable portion such that the non-anodizable portion adheres to the anodizable portion. 
 
     
     
       9. The method of  claim 1 , wherein the enclosure further comprises a support piece positioned adjacent the non-anodizable portion. 
     
     
       10. The method of  claim 9 , wherein the non-anodizable portion is coupled with the support piece with an adhesive. 
     
     
       11. The method of  claim 9 , wherein the non-anodizable portion is coupled with the support piece using a welding process. 
     
     
       12. The method of  claim 9 , the non-anodizable portion is coupled with the support piece with one or more fasteners. 
     
     
       13. A method of manufacturing an enclosure for a consumer product that includes a non-anodizable portion and an anodizable portion, the method comprising:
 positioning the non-anodizable portion within a pocket of the anodizable portion; 
 removing a portion of the non-anodizable portion and the anodizable portion such that the non-anodizable portion and the anodizable portion cooperate to form a curved surface; 
 removing the non-anodizable portion from the pocket; 
 subsequent to the removing, forming an anodic film on the anodizable portion; and 
 reforming the curved surface by securing the non-anodizable portion within the pocket. 
 
     
     
       14. The method of  claim 13 , further comprising:
 dyeing the anodic film prior to securing the non-anodizable portion with the anodizable portion. 
 
     
     
       15. The method of  claim 13 , wherein the non-anodizable portion is comprised of at least one of polycarbonate, ABS, PEI, PPSU, PS, or PEEK. 
     
     
       16. A method of manufacturing an enclosure for a consumer product, the enclosure including a non-metal portion and a metal portion, the method comprising:
 positioning the non-metal portion adjacent the metal portion; 
 forming a contoured surface by co-machining the non-metal portion and the metal portion, wherein the contoured surface includes a non-metal surface of the non-metal portion and a metal surface of the metal portion; 
 decoupling the non-metal portion and the metal portion; 
 subsequent to the decoupling, forming an anodic film on the metal surface; and 
 coupling the non-metal portion with the metal portion such that the contoured surface is reformed. 
 
     
     
       17. The method of  claim 16 , wherein the contoured surface has a spline shape. 
     
     
       18. The method of  claim 16 , wherein positioning the non-metal portion adjacent the metal portion comprises:
 adhering the non-metal portion with the metal portion using an adhesive. 
 
     
     
       19. The method of  claim 16 , wherein the non-metal portion is positioned within a pocket of the metal portion. 
     
     
       20. The method of  claim 16 , wherein coupling the non-metal portion with the metal portion includes positioning the contoured surface against a datum surface having a shape corresponding to the contoured surface.

Description:
FIELD 
     This disclosure relates generally to manufacture of composite parts having non-metal portions and metal portions, where the metal portions are anodized. In particular embodiments, the methods and systems described can be used in the manufacture of enclosures for consumer products, such as enclosures for consumer electronic products. 
     BACKGROUND 
     Many commercial products include portions that are made of more than one type of material, such as metal portions and plastic portions, which are assembled together into a single part. Often, an anodizing process is used to provide a protective and cosmetically appealing surface finish to the metal portions of these composite parts. During an anodizing process, a metal part is exposed to an electrolytic process whereby the metal part acts as an anode. The process forms a metal oxide film or anodic film on surfaces of metal. The metal oxide layer can enhance the durability and corrosion resistance of the part. In addition, the metal oxide layer has a porous structure that can accept any of a number of dyes. These dyes can be infused within the porous structures of the metal oxide to give the part a particular color. 
     Although anodizing can provide numerous benefits, the anodizing process itself can complicate the manufacturing process when a part is a composite part that includes portions made of materials that are not anodizable, such as plastic, glass or ceramic. This can be especially problematic when the anodizable metal portions are directly adjacent the non-anodizable portions. This arrangement creates gaps, even if small, between the anodizable metal portions and non-anodizable portions where chemicals from an anodizing process can get trapped. The trapped chemicals can leak out or otherwise disrupt subsequent operations. For example, the trapped chemicals can inhibit the uptake of dyes within portions of the anodic films and create visible defects, which detract from the cosmetic appearance of the composite parts. 
     SUMMARY 
     This paper describes various embodiments that relate to systems and methods of assembling a part having a non-metal portion, such as a plastic portion, and a metal portion that is anodizable. The systems and methods described can be used in the manufacture of enclosures for electronic devices. 
     According to one embodiment, a method of manufacturing a composite part that includes a non-anodizable portion coupled with an anodizable portion is described. The method includes co-machining a surface of the non-anodizable portion with a surface of the anodizable portion such that the surface of the non-anodizable portion cooperates with the surface of the anodizable portion to form a continuous surface. The method also involves decoupling the non-anodizable portion from the anodizable portion. The method further includes anodizing the anodizable portion forming an anodic film on at least the surface of the anodizable portion that was co-machined. The method additionally includes securing the non-anodizable portion with the anodizable portion such that the continuous surface is reformed. 
     According to an additional embodiment, a method of manufacturing a composite part that includes a non-anodizable portion and an anodizable portion is described. The method includes forming an anodic film on the anodizable portion. The anodic film has a surface corresponding to an exterior surface of the part. The method also includes securing the non-anodizable portion with the anodizable portion. The non-anodizable portion has a shape that is approximate a final shape. The method further includes removing a portion of the non-anodizable portion such that the non-anodizable portion takes on the final shape. The removing includes contacting the surface of the anodic film and a surface of the non-anodizable portion with an abrasive material that preferentially removes non-anodizable portion over the anodic film such that the surface of the anodic film and the surface of the non-anodizable portion cooperate to form a contoured surface. 
     According to a further embodiment, a method of manufacturing a composite part that includes a non-anodizable portion and an anodizable portion is described. The anodizable portion includes a pocket. The method includes positioning the non-anodizable portion within the pocket of the anodizable portion. The method further includes applying a first pressure in a first direction to non-anodizable portion such that a surface of the non-anodizable portion is in an inset position with respect to a surface of the anodizable portion. The method additionally includes aligning the part with a datum surface having a shape corresponding to a contoured surface. The method also includes applying a second pressure in a second direction opposite the first direction to the non-anodizable portion against the datum surface such that the surface of the non-anodizable portion and the surface of the anodizable portion cooperate to form the contoured shapes 
     These and other embodiments will be described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIGS. 1A-1D  show a composite part undergoing an anodizing process. 
         FIGS. 2A-2F  show a composite part undergoing an anodizing manufacturing process, in accordance with described embodiments. 
         FIGS. 3A-3D  show composite parts having securing mechanisms, in accordance with described embodiments. 
         FIGS. 4A-4E  show a composite part manufactured using a fixture, in accordance with described embodiments. 
         FIG. 5  shows a flowchart indicating a high-level process for forming a composite part in accordance with embodiments described with reference to  FIGS. 1A-4E . 
         FIGS. 6A-6C  show a composite part manufactured with a machining process implemented after an anodizing process is performed, in accordance with described embodiments. 
         FIG. 7  shows a flowchart indicating a high-level process for forming a composite part in accordance with embodiments described with reference to  FIGS. 6A-6C . 
         FIGS. 8A-8E  show a composite part manufactured using a gap filling process. 
         FIG. 9  shows a flowchart indicating a high-level process for forming a composite part in accordance with embodiments described with reference to  FIGS. 8A-8E . 
     
    
    
     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 embodiment. To the contrary, they are intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims. 
     Described herein are methods and systems for manufacturing composite parts that include anodizable portions (e.g., made of an anodizable metal such as aluminum or aluminum alloy) and non-anodizable portions (e.g., made of plastic, ceramic or glass) such that interfaces between the anodizable portions and the non-anodizable portions are free of visible defects. In particular, the methods relate to manufacturing methods that are compatible with anodizing processes so as to avoid defects related to anodizing processes. In particular embodiments, the methods involve avoiding trapping of anodizing chemicals within a gap between an anodizable portion and a non-anodizable portion, which prevents the anodizing chemicals from disrupting the uptake of dye in a post-anodizing dyeing process. The result is a composite part that is cosmetically appealing and free of visible defects. 
     In some embodiments, the non-anodizable portion is removed from the anodizable portion prior to an anodizing process so that the non-anodizable portion is not subject to the anodizing process. The non-anodizable portion can then be reassembled with the anodizable portion after the anodizing process is complete. In other embodiments, the methods involve assembling the anodizable and non-anodizable portions together prior to an anodizing process such that a gap between the anodizable and non-anodizable portions is filled. This way, when the assembled composite part is subject to an anodizing process, anodizing chemicals are prevented from entering the gap and thereby prevented from disrupting a subsequent dyeing process. In these embodiments, the non-anodizable portions should be made of a material that is compatible with an anodizing process, such as certain types of plastics. 
     The methods described herein are well suited for providing both protective and attractive surfaces to visible portions of consumer products. For example, methods described herein can be used to provide protective and cosmetically appealing exterior portions of metal enclosures and casings for electronic devices, such as those manufactured by Apple Inc., based in Cupertino, Calif. In particular embodiments, the methods are used to form protective coatings for exterior metallic surfaces of computers, portable electronic devices and/or accessories for electronic devices. 
     These and other embodiments are discussed below with reference to  FIGS. 1-9 . 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. 
     As described above, anodizing can provide durable and cosmetically appealing coatings to metal surfaces. However, the anodizing process itself can cause difficulty when manufacturing composite parts that include anodizable portions, such as those made of anodizable metal material like aluminum or aluminum alloy, and non-anodizable portions, such as those made of plastic, ceramic or glass. To illustrate,  FIGS. 1A-1D  show part  100 , which includes anodizable portion  102  and non-anodizable portion  104 , undergoing an anodizing process. 
       FIG. 1A  shows a cross-section view of part  100  prior to an anodizing process. Non-anodizable portion  104 , which can correspond to a plastic, glass or ceramic material, is positioned within pocket  106  formed within anodizable portion  102 . Anodizable portion  102  can correspond to an anodizable material such as aluminum or aluminum alloy. Gaps  108  form between anodizable portion  102  and non-anodizable portion  104  when assembled together. Even if anodizable portion  102  and non-anodizable portion  104  are in contact along an interface between anodizable portion  102  and non-anodizable portion  104 , small gaps  108  will form. 
       FIG. 1B  shows a cross-section view of part  100  after an anodizing process where exposed surface portions of anodizable portion  102  are converted to anodic film  110 . During the anodizing process, part  100  is immersed in an anodizing electrolyte and a voltage is applied such that exposed surfaces of anodizable portion  102  oxidize to a corresponding metal oxide material. During the anodizing process chemicals  112  get trapped within gaps  108  and are not easily removable using rinsing or other standard techniques if gaps  108  are small. Note that since non-anodizable portion  104  is also immersed in the anodizing electrolyte and subject to anodizing conditions, non-anodizable portion  104  needs to be made of a material that is chemically resistant to becoming denatured or damaged by such exposure. 
       FIG. 1C  shows a cross-section view of part  100  after a dyeing process where dye is infused within anodic film  110  to give anodic film  110  a desired color. During the dyeing process, chemicals  112  can spread into adjacent portions of anodic film  110  and inhibit the uptake of dye in these areas forming visible defects  114  that can appear as irregular shaped blotches.  FIG. 1D  shows a top-down view of part  100  with dyed anodic film  110  and visible defects  114  formed at an interface between anodic film  110  and non-anodizable portion  104 . 
     The methods described herein involve forming a composite part such that the visible defect problems associated with anodizing processes described above are eliminated. In some embodiments, the methods involve removing the non-anodizable portion of the part, anodizing the anodizable portion, and then reassembling the non-anodizable portion back into the part. These embodiments are described below with reference to  FIGS. 1-7 . In other embodiments, the methods involve filling the gap at the interface between the non-anodizable and anodizable portions, and then anodizing the composite part. Since the gap is filled, this prevents anodizing chemicals from entering and getting trapped within the gap. These embodiments are described below with reference to  FIGS. 8-9 . 
       FIGS. 2A-2F  show part  200 , which includes anodizable portion  202  and non-anodizable portion  204 , undergoing an anodizing manufacturing process in accordance with described embodiments.  FIG. 2A  shows a cross-section view of part  200  after non-anodizable portion  204  is positioned within pocket  206  formed within anodizable portion  202 . Anodizable portion  202  can be made of any suitable anodizable material, including metals such as aluminum, titanium, zinc, magnesium, niobium, zirconium, hafnium, tantalum, and suitable alloys thereof. In some embodiments, anodizable portion  202  is made of an aluminum alloy having sufficient strength for forming an enclosure or a portion of an enclosure for a consumer product, such as a consumer electronic device. Anodizable portion  202  can be shaped to have pocket  206  using any suitable technique, including machining techniques that give anodizable portion  202  a shape roughly corresponding to a final shape of anodizable portion  202 . 
     Non-anodizable portion  204  can be made of any suitable material that is generally not anodizable, such as plastic, glass, and/or ceramic. In some embodiments, non-anodizable portion  204  is made of a plastic material having sufficient strength and durability for forming exterior portions of an enclosure or a portion of an enclosure for a consumer product, such as a consumer electronic device. In some embodiments non-anodizable portion  204  is made of a relatively rigid material, such as hard plastic, while in other embodiments non-anodizable material is made of a relatively compliant material, such as a soft plastic, silicone, or rubber. In some embodiments, the material for non-anodizable portion  204  is chosen for other physical properties such as electrical capacitance, dielectric constant, radio frequency (RF) transparency, color, and/or resistance to fading. In particular embodiments, non-anodizable portion  204  is made of a substantially RF transparent material, such as an RF transparent plastic material, so that RF communication can pass through non-anodizable portion  204  to and/or from an RF antenna positioned within the electronic device. In some embodiments, non-anodizable portion  204  is dyed to have a color that matches that of a subsequently formed dyed anodic film that is adjacent non-anodizable portion  204 . 
     In some embodiments, non-anodizable portion  204  starts out as a rigid material that is pressed within pocket  206 . In other embodiments, non-anodizable portion  204  starts out as a molten material that is molded into pocket  206  using, for example an injection molding process, and allowed to harden within pocket  206 . This can give non-anodizable portion  204  a shape that is near a final shape (near net shape). In some embodiments, pocket  206  and/or non-anodizable portion  204  are shaped to provide clearance  208  between non-anodizable portion  204  and anodizable portion  202  within pocket  206 . Clearance  208  can be provided to accommodate the formation of an anodic film formed within pocket  206  in a subsequent anodizing process. In addition, or alternatively, clearance  208  can provide room for a subsequently applied adhesive used in some embodiments to adhere non-anodizable portion  204  with anodizable portion  202 . The size and shape of clearance  208  can vary depending upon design requirements. According to some embodiments, surface  205  of non-anodizable portion  204  is not flush with surface  203  of anodizable portion  204 . For example, surface  205  of non-anodizable portion  204  can extend above at an offset a distance  207  from surface  203  of anodizable portion  204 . In other embodiments (not shown), surface  203  of anodizable portion  204  extends above surface  205  of non-anodizable portion  204 . 
       FIG. 2B  shows part  200  after a co-machining process where non-anodizable portion  204  and anodizable portion  202  are machined together such that surface  203  and surface  205  cooperate to form a continuous surface  210 . Continuous surface  210  can be machined to have any suitable shape using any suitable machining process. In some cases, continuous surface  210  is planarized, using for example a grinding or polishing operation, to form a substantially flat or planar shape. In other cases, continuous surface  210  is machined and/or polished/ground to have a curved shaped. Non-anodizable portion  204  can be secured within pocket  206  during the machining operation using any suitable method, including use of an adhesive, one or more fasteners, or by pressing non-anodizable portion  204  within pocket  206  such that non-anodizable portion  204  is held in place by friction. 
     After continuous surface  210  is formed, at  FIG. 2C  non-anodizable portion  204  is removed from pocket  206  and anodizable portion  204  is exposed to an anodizing process. During anodizing, anodizable portion  202  is placed in an electrolytic bath and a voltage is applied such that exposed surface portions of anodizable portion  202  are converted to anodic film  212 , including at surface  203 . Anodic film  212  can correspond to a protective outer coating for part  200 . In some embodiments, surface  214  of anodizable portion  202  within pocket  206  are also anodized such that anodic film  212  covers interior surface of pocket  206 . In other embodiments, surface  214  is masked (not shown) prior to anodizing such that anodic film  212  forms only on surface  203  and does not form within pocket  206 . Any suitable anodizing process can be used. In particular embodiments, anodizing processes that are conducive to forming anodic film  203  of sufficient durability and aesthetic appeal for an enclosure for an exterior surface for an enclosure for a consumer electronic product is used. 
     After anodizing, in some embodiments one or more operations can be performed to compensate for changes in the dimensions of pocket  206  due to the addition of anodic film  212  within the pocket  206 . For example, interior walls of pocket  206  can be machined or etched (e.g., laser etched) to remove portions of, or all of, anodic film  206  within pocket  206 . After anodizing, part  200  can be rinsed and cleaned. 
     At  FIG. 2D , anodic film  212  can optionally be dyed using any suitable dyeing process. Many anodic dyeing processes involve infusing dye particles, such as organic or inorganic pigments, into anodic pores within anodic film  212 . In some embodiments, anodic film  212  is dyed to have substantially the same color as a color of non-anodizable portion  204 . Since anodizing chemicals are not trapped in any gaps, the dye particles are unimpeded from infusing within anodic film  212 . Thus, the dye can be evenly infused within anodic film  212  giving anodic film  212  a continuous dyed color. In some embodiments, one or more sealing operations can be used to seal the anodic pores within anodic film  212  after the dyeing process. 
     At  FIG. 2E , non-anodizable portion  204  is replaced within pocket  206  such that surface of non-anodizable portion  204  is substantially flush with surface  203  of anodic film  212 , thereby reforming continuous surface  210 . Since non-anodizable portion  204  is assembled within part  200  after an anodizing process, there is no gap where anodizing chemicals can get trapped. Thus, anodic film  212  retains its evenly dyed color without visible defects associated with the anodizing process.  FIG. 2F  shows a top-down view of part  200  with dyed anodic film  212  with no visible defects at an interface region  218  between anodic film  212  and non-anodizable portion  204 . 
     In some cases, non-anodizable portion  204  is inserted within pocket  206  using a “soft tooling” technique where tools made of a relatively soft material such as silicone are used to position, insert and/or press non-anodizable portion  204  within pocket  206 . This way, anodic film  212  is prevented from damage due to contact with harder tools. In some embodiments, non-anodizable portion  204  is secured within pocket  206  by frictional force, such as by press fitting. In other embodiments, non-anodizable portion  204  is secured within pocket  206  using one or more other mechanisms, which will be described in detail below with reference to  FIGS. 3A-3D . In some embodiments, a fixture is used to properly position non-anodizable portion  204  within pocket  206 . Some of these embodiments are described below with reference to  FIGS. 4A-4E . 
     Note that since non-anodizable portion  204  is not subject to an anodizing process, non-anodizable portion  204  is not limited to materials that are chemically resistant to anodizing electrolytes and anodizing conditions, unlike non-anodizable portion  104  described above with reference to  FIGS. 1A-1D . This allows for use of a broader set of materials that can be used to form non-anodizable portion  204 . For example, non-anodizable portion  104  can be limited to polyether ether ketone (PEEK), polyphenylsulfone (PPSU), and plastic materials that are generally chemically resistant to anodizing processes. In contrast, the scope of materials for non-anodizable portion  204  can be broadened vastly. For example, suitable materials can include anodizing resistant materials such as PEEK and PPSU and also other materials such as silicone-based materials, polycarbonate, acrylonitrile butadiene styrene (ABS), polyetherimide (PEI), and polysulfone (PS), to name a few. 
     After non-anodizable portion  204  is inserted within pocket  206 , in some cases one or both of surfaces  203  and  205  are finished again, using for example a gentle buffing operation, to assure that continuous surface  210  is sufficiently retained and continuous without significant offset between surfaces  203  and  205 . If not already done, in some embodiments anodic film  212  infused with dye to impart a desired color to anodic film  212  and/or sealed using a sealing process. 
     As described above, in some embodiments, a non-anodizable portion can be secured to an anodizable portion of a composite part using one or more mechanisms.  FIGS. 3A-3D  illustrate some suitable securing mechanisms.  FIG. 3A  shows part  300 , which includes non-anodizable portion  304  inserted within pocket  306  of anodizable portion  302 . Anodic film  312  is formed on anodizable portion  302 . Adhesive  308  is applied to internal surfaces within pocket  306  prior to inserting non-anodizable portion  304  such that adhesive  308  is between non-anodizable portion  304  and anodizable portion  302 . Adhesive can be any suitable adhesive, including epoxy and other liquid adhesives. In some embodiments, clearance  310  is provided between non-anodizable portion  304  and anodizable portion  302  to accommodate excess portions of adhesive  308 . 
       FIG. 3B  shows part  320 , which includes non-anodizable portion  324  inserted within pocket  326  of anodizable portion  322 , with anodic film  332  formed on anodizable portion  322 . Fasteners  328  are driven through anodizable portion  322  and a portion of non-anodizable portion  324  via surface  330  securing non-anodizable portion  324  within pocket  326  and to anodizable portion  322 . Fasteners  328  can be stop short of penetrating through surface  325  of non-anodizable portion  324  in order to prevent marring of continuous surface  334 . Fasteners  328  can be any suitable type of fastener, including pins or screws, and can be made of any suitable material. In some embodiments, fasteners  328  are metal pins that are bent or swaged at surface  330 . In other embodiments, fasteners  328  are made of plastic that are fused with non-anodizable portion  324  by heat staking methods. In some embodiments, fasteners  328  are threaded. 
       FIG. 3C  shows part  340 , which includes non-anodizable portion  344  inserted within pocket  346  of anodizable portion  342 , with anodic film  352  formed on anodizable portion  342 . Part  340  includes support piece  348  that is positioned adjacent non-anodizable portion  344  at interface  350 . Non-anodizable portion  344  can be coupled with support piece  348  at interface  350  using any suitable mechanism. For example, an adhesive can be applied between non-anodizable portion  344  and support piece  348  at interface  350 . Alternatively or additionally, one or more fasteners can be driven through support piece  348  and a portion of non-anodizable portion  344 , similar to fasteners  328  described above with reference to  FIG. 3B . For example, the fasteners can be metal pins or screws or plastic fasteners that are fused with non-anodizable portion  344  and/or support piece  348  using heat staking methods. Support piece  348  can be made of any suitable material. In some embodiments, support piece  348  is made of a material suitably rigid for providing rigid support for non-anodizable portion  344  within pocket  346 . 
     In some embodiments, support piece  348  is made of a material that can be welded with non-anodizable portion  344  at interface  350 , using a laser welding process. For example, support piece  348  can be made of a laser-transparent material (e.g., transparent to infrared (IR) laser beam) and non-anodizable portion  344  can be made of a laser-absorptive material (e.g., absorbs IR laser beam energy). A laser beam (e.g., IR laser beam) can be directed toward surface  354  of support piece  348  such that the laser beam transmits through support piece  348  until the laser beam reaches laser-absorptive non-anodizable portion  344  at interface  350 . Energy from the laser beam will melt non-anodizable portion  344  at interface  350  and meld non-anodizable portion  344  to support piece  348  at interface  350 . In this way, non-anodizable portion  344  can be secured to support piece  348  within pocket  346 . In other embodiments, non-anodizable portion  344  is made of a laser-transparent material and support piece  348  is made of a laser-absorptive material. The laser beam can then be directed at surface  356  of non-anodizable portion  344  such that the laser beam transmits through non-anodizable portion  344  and melds support piece  348  at interface  350 . In other embodiments, non-anodizable portion  344  and support piece  348  are ultrasonically welded together at interface  350 . 
       FIG. 3D  shows part  360 , which includes non-anodizable portion  364  inserted within pocket  366  of anodizable portion  362 , with anodic film  372  formed on anodizable portion  362 . Non-anodizable portion  364  includes snap-fit features  368  that each has an undercut geometry. Anodizable portion  362  includes corresponding features  370  within pocket  366  that each has a shape for pairing with a corresponding snap-fit feature  368 . Snap-fit features  368  have sloped surfaces that allows non-anodizable portion  364  to slide within pocket  366  when non-anodizable portion  364  is inserted within pocket  366 . The undercut geometry of snap-fit features  368  engage with corresponding features  370  and secure non-anodizable portion  364  within pocket  366  once inserted. Note that snap-fit features  368  and corresponding features  370  can have any suitable shape for sufficiently engaging and securing non-anodizable portion  364  within pocket  366  and are not limited to the particular shapes illustrated in  FIG. 3D . In addition, the number of matching snap-fit features  368  and corresponding features  370  can vary depending on design requirements. 
     It should be noted that one or more of the securing mechanisms described above with reference to  FIGS. 3A-3D  can be combined in order to secure a non-anodizable portion within a pocket of an anodizable portion, in accordance with described embodiments. For example, the snap-fit features  368  of  FIG. 3D  can be combined with use of an adhesive and/or fastener to further secure non-anodizable portion  364  within pocket  366 . Likewise, the welding methods described above with reference to  FIG. 3C  can be combined with the use of an adhesive and/or fastener to further secure non-anodizable portion  344  within pocket  346 . 
     As described above, according to some embodiments a fixture can be used to properly position a non-anodizable portion with an anodizable portion. To illustrate,  FIGS. 4A-4E  show cross-section views of portions of part  400  manufactured using a fixture in accordance with described embodiments.  FIG. 4A  shows part  400 , which includes anodizable portion  402  and non-anodizable portion  404  that is positioned within pocket  406  of anodizable portion  402 . Part  400  also includes support piece  408 , which provides additional support for non-anodizable portion  404  within pocket  406 . In some embodiments, clearance  414  is provided between portions of non-anodizable portion  404  and portions of anodizable portion  402  and support piece  408  in order accommodate adhesive that is applied in a subsequent repositioning process. In addition, clearance  414  can also be provided to make room for portions of non-anodizable portion  404  during the subsequent repositioning process, which is described in detail below with reference to  FIG. 4C . 
     Part  400  has continuous surface  410  that includes surface  403  of anodizable portion  402  and surface  405  of non-anodizable portion  404 . Continuous surface  410  can be formed by co-machining surface  403  and surface  405  using, for example, one or more cutting, milling, polishing, etching, and buffing operations. In some embodiments, continuous surface  410  has a spline shape. In some embodiments, continuous surface  210  corresponds to an exterior surface of an enclosure of an electronic device and surface  412  corresponds to an internal surface of the enclosure. One or more of non-anodizable portion  404  and support piece  408  can be made of RF transparent plastic(s) that allow RF transmission to/from a RF antenna housed within the enclosure. 
       FIG. 4B  shows part  400  after non-anodizable portion  404  is removed from pocket  406  and part  400  is exposed to an anodizing process. During the anodizing process, exposed surfaces of anodizable portion  402  are converted to anodic film  416 . Thus, surface  403  corresponds to a surface of anodic film  416 . In some embodiments, support piece  408  is coupled to anodizable portion  402  during the anodizing process. Thus, in these embodiments support piece  408  should be made of a material that is substantially resistant to anodizing chemical and anodizing conditions, such as a PEEK or PPSU plastic material. After anodic film  146  is formed, anodic film  416  can be optionally dyed to impart a desired color to anodic film  416 . In some embodiments an adhesive, such as epoxy, is deposited within pocket  406 . 
       FIG. 4C  shows part  400  after non-anodizable portion  404  is repositioned within pocket  406 . In some embodiments, pressure is applied to non-anodizable portion  404  in a first direction such that non-anodizable portion  404  is pushed into pocket  406  in an inset position, which is a farther distance within pocket  406  compared to when co-machined at  FIG. 4A . In the inset position, surface  405  of non-anodizable portion  404  is inset a distance from surface  403  of anodic film  416 . In some embodiments, non-anodizable portion  404  is pushed into pocket  406  such that clearance  414  is consumed. In some embodiments, pressure is applied to non-anodizable portion  404  using a soft tooling technique where tools made of a relatively soft material such as silicone are used to position, insert and/or press non-anodizable portion  404  within pocket  406 . This way, anodic film  416  is prevented from damage due to contact with harder tools. 
     After non-anodizable portion  404  has been positioned within pocket  406 , at  FIG. 4D  part  400  is positioned within fixture  418  such that surface  403  of anodic film  416  is positioned against datum surface  420  of fixture  418 . Datum surface  420  has a shape that corresponds to the shape of contoured surface  410 . For example, if continuous surface  410  has a spline shape, datum surface  420  will have a corresponding spline shape. Note that datum surface  420  can have any suitable shape that corresponds to a shape of a contoured surface of a part. For example, in other embodiments where the contoured surface is substantially flat or planar, such as described above with reference to  FIGS. 2A-2F , datum surface  420  will have a correspondingly flat or planar shape. 
     After part  400  is placed within fixture  418 , a second pressure can be applied in second direction opposite the first direction in order to pull non-anodizable portion  404  form its inset position and reform continuous surface  410 . In some embodiments, this is accomplished using vacuum pressure. For example, fixture  418  includes holes  422  that have openings at datum surface  420 . Holes  422  are connected with a vacuum system such that vacuum suction pulls non-anodizable portion  404  from the inset position shown in  FIG. 4C  and realigns surface  405  of non-anodizable portion  404  with surface  403  of anodic film  416 . The number and size (diameter) of holes  422  can vary depending on the size of non-anodizable portion  404 . In some cases, when surface  405  of non-anodizable portion  404  is realigned with surface  403  of anodic film  416 , clearance  414  is reformed. 
     After non-anodizable portion  404  is realigned, one or more additional methods can be implemented to secure non-anodizable portion  404  within pocket  406 . For example, one or more of the securing mechanisms described above with reference to  FIGS. 3A-3D  can be implemented. In embodiments where an adhesive is positioned within clearance  414 , the adhesive can be allowed to cure, thereby fixing non-anodizable portion  404  within pocket  406 . In some embodiments, anodic film  405  can be dyed to impart a desired color to anodic film  405 .  FIG. 4E  shows part  400  after being removed from fixture  418 . As shown, surface  403  of anodic film  416  is realigned with surface  405  of non-anodizable portion  404  forming contoured surface  410  that does not include offsets. In addition anodic film  416  is cosmetically appealing and free of visible defects. 
       FIG. 5  shows flowchart  500  indicating a high-level process for forming a composite part that includes a non-anodizable portion coupled with an anodizable portion in accordance embodiments described above with reference to  FIGS. 1A-4E . The anodizable portion can be made of any suitable anodizable material, such as aluminum and suitable alloys thereof. The non-anodizable portion can be made of any suitable material that is generally not capable of forming an anodic film, including plastic materials. In some embodiments, the plastic material is an RF transparent plastic material. In some embodiments, the non-anodizable portion is positioned within a pocket of the anodizable portion. 
     At  502 , a surface of the non-anodizable portion is co-machined with a surface of the anodizable portion forming a contoured surface. The co-machining can include one or more machining operations, including suitable cutting, milling, polishing, etching, and buffing operations. The contoured surface can have any suitable shape, including substantially planar or curved. In some embodiments, the contoured surface has a spline shape. At  504 , the non-anodizable portion is decoupled from the anodizable portion. In embodiments where the non-anodizable portion is positioned within a pocket, the non-anodizable portion is removed from the pocket. 
     At  506 , the anodizable portion is anodized forming an anodic film on at least the surface of the anodizable portion that was co-machined. In some embodiments, the anodic film is formed on surfaces within the pocket of the anodized portion. Since the non-anodizable portion is not coupled with the anodizable portion, there are no gaps at interfaces between the anodizable portion and non-anodizable portion for chemicals related to the anodizing process can get trapped. At  508 , the anodic film is optionally dyed using one or more dyeing operations. The one or more dyes can infuse unimpeded within pores of the anodic film without formation of visible defects related to trapped anodizing-related residues. 
     At  510 , the non-anodizable portion is secured to the anodizable portion such that the contoured surface is reformed. Any suitable securing mechanism can be used, including using one or more press fit, adhesive, fastener(s), welding, snap fit, and heat stake methods described above. At  512  the composite part can optionally be finished to remove any offsets between the surface of the non-anodizable portion and the anodizable portion that may have been formed and to assure that the contoured surface is retained. The finishing method should be gentle enough not to visibly damage the anodic film. Suitable methods may include a buffing or light polishing process. The anodic film can optionally be dyed. In some embodiments, this is the first time the anodic film is dyed. In other embodiments, the anodic film is dyed for a second or subsequent times. 
     According to some embodiments, a machining process is implemented after an anodizing process is performed. To illustrate  FIGS. 6A-6C  show cross-section views of part  600  manufactured using such a process.  FIG. 6A  shows anodizable portion  602  after an anodizing process such that anodic film  612  is formed. Surface  603  of anodic film  602  corresponds to an exterior surface of part  600 . Anodizable portion  602  includes pocket  606 , which has a size and shape for accepting a non-anodizable portion. After anodizing, anodic film  612  is optionally dyed using one or more anodic film dyeing operations and/or sealed using one or more sealing operations. 
       FIG. 6B  shows part  600  after non-anodizable portion  604  is positioned within pocket  606 . In some embodiments, non-anodizable portion  604  is inserted using a soft tooling technique, as described above, so as not to damage anodic film  612 . Non-anodizable portion  604  can be formed to have a shape such that non-anodizable portion  604  snuggly fits within pocket  606 . In some embodiments, non-anodizable portion  604  has a shape such that clearance  608  is provided between non-anodizable portion  604  and anodizable portion  602 . In some embodiments, one or more securing mechanisms, such as one or more press fit, adhesive, fastener(s), welding, snap fit, and heat stake methods described above, is used to secure non-anodizable portion  604  within pocket  606 . 
     As shown, non-anodizable portion  604  has surface  605  that is offset or sits proud a distance  607  with respect to surface  203  of anodic film  612 .  FIG. 6C  shows part  600  after a removal process where a portion of non-anodizable portion  604  corresponding to distance  607  is removed. After the removal process, surface  605  of non-anodizable portion  604  is flush with and cooperates with surface  603  of anodic film  612  to form contoured surface  610 . The removal process should be one that preferentially removes non-anodizable portion  604  over anodic film  612  and does not substantially mar anodic film  612 . Thus, a relatively gentle removal process is preferred. In particular embodiments, a cutting, grinding, or polishing operation using an abrasive that preferentially removes the material of non-anodizable portion  604  is used. The abrasive contacts both surface  605  and surface  603  but is made of material that preferentially removes non-anodizable portion  604 . The nature and type of the abrasive will depend on the material of non-anodizable portion  604  as well as the hardness of anodic film  612 . The materials chosen for non-anodizable portion  604  can vary depending on application requirements as well as the type of abrasive used. In some applications suitable include polycarbonate, ABS, PEI, PPSU, PS, and PEEK. 
       FIG. 7  shows flowchart  700  indicating a high-level process for forming a composite part that includes a non-anodizable portion coupled with an anodizable portion in accordance with embodiments described above with reference to  FIGS. 6A-6C . At  702 , the anodizable portion is anodized forming an anodic film on the anodizable portion. In some embodiments, the anodic film has a surface corresponding to an exterior surface of the part. At  704 , the anodic film is optionally dyed using one or more anodic dyeing operations. 
     At  706 , the non-anodizable portion is secured with the anodizable portion. The non-anodizable portion has a shape that is approximate to a final shape of the non-anodizable portion. This way, a minimal amount of material from the non-anodizable portion needs to be removed during a subsequent removal process. In some embodiments, the non-anodizable portion is secured within a pocket of the anodizable portion. Any suitable securing mechanism can be used, including using one or more press fit, adhesive, fastener(s), welding, snap fit, and heat stake methods described above. 
     At  708 , a portion of the non-anodizable portion is removed such that the non-anodizable portion takes on the final shape. The removing process can include contacting the surface of the anodic film and a surface of the non-anodizable portion with an abrasive material that preferentially removes non-anodizable portion over the anodic film such that the surface of the anodic film and the surface of the non-anodizable portion cooperate to form a contoured surface. At  710 , the composite part can be optionally dyed. In embodiments where the anodic film is not dyed at  704 , this corresponds to the first time that the anodic film is dyed. In embodiments where the anodic film is dyed at  704 , the anodic film can be dyed for a second or subsequent number of times. 
     As described above, in some cases methods involve filling the gap at the interface between the non-anodizable and anodizable portions and then anodizing the composite part.  FIGS. 8A-8E  show cross-section views of a part  800  manufactured using such a gap filling process. At  FIG. 8A , adhesive layer  801  is deposited onto interior surfaces of pocket  806  of anodizable portion  802 . Adhesive layer  801  can include any suitable material, including epoxy material. At  FIG. 8B , non-anodizable portion  804  is positioned within pocket  806  such that adhesive layer  801  secures non-anodizable portion  804  to anodizable portion  802 . In some embodiments, additional securing mechanisms such as fastener(s), welding, snap fit, and heat stake methods, such as described above, can be used. In some embodiments, clearance  508  is provided to accommodate adhesive layer  801 . Adhesive layer  801  can fill gaps  807  that exist at the interface between non-anodizable portion  804  and anodizable portion  802 . 
     At  FIG. 8C , surface  805  of non-anodizable portion  804  is co-machined with surface  803  of anodizable portion  802  forming contoured surface  810 . Contoured surface  810  can have any suitable shape, including a planar shape or curved (e.g., spline) shape. Continuous surface  810  can be formed using any suitable shaping operation, including one or more cutting, milling, polishing, etching, and buffing operations. Once contoured surface  810  is formed, at  FIG. 8D  part  800  is anodized forming anodic film  812  on exposed surfaces of anodized portion  802 . Since anodizing is a conversion process, surface  803  now corresponds to an exposed surface of anodic film  812  and contoured surface  810  is retained. Since gaps  807  are filled with adhesive layer  801 , the anodizing chemicals from the electrolytic bath used during anodizing are prevented from entering and getting trapped within the gaps  807 . 
     At  8 E, anodic film is optionally dyed using an anodic dyeing operation to give anodic film  812  a desired color. Since gaps  807  are free from anodizing-related chemicals, the dye can become evenly infused within anodic film  812  without forming visible defects near gaps  807 . Part  800  also retains contoured surface  810  giving part  800  a continuous and aesthetically appealing look and feel. 
       FIG. 9  shows flowchart  900  indicating a high-level process for forming a composite part that includes a non-anodizable portion coupled with an anodizable portion in accordance embodiments described above with reference to  FIGS. 8A-8E . At  902 , an adhesive layer is deposited on a surface of the anodizable portion. In some embodiments, the surface corresponds to interior surfaces of a pocket formed within the anodizable portion. The adhesive can include any suitable material, such as epoxy. The thickness of the adhesive layer can be chosen to provide sufficient blockage of anodizing-related chemicals in a subsequent anodizing process. 
     At  904 , the non-anodizable portion of the part is coupled to the anodizable portion via the adhesive layer. In some embodiments, this involves inserting the non-anodizable portion within the pocket of the anodizable portion. In some cases, a clearance between the non-anodizable portion and the anodizable portion is provided in order to accommodate excess adhesive material of the adhesive layer. In some cases, the non-anodizable portion is further secured to the anodizable portion using one or more fasteners, press fit, weld, snap fit, and heat stake methods. 
     At  906 , a surface of the non-anodizable portion is co-machined with a surface of the anodizable portion forming a contoured surface. The contoured surface can correspond to an exterior surface of the part. At  908 , the part is exposed to an anodizing process such that an anodic film is formed on the anodizable portion. The adhesive layer prevents entry of chemicals from the anodizing process from getting trapped within gaps at interfaces between the non-anodizable portion and the anodizable portion. After anodizing, the contoured surface corresponds to the surface of the non-anodizable portion and a surface of the anodic film. At  910 , the anodic film is optionally dyed using one or more dyeing operations. The resultant composite part has an aesthetically pleasing contoured surface and is substantially free of visible defects. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not target to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20140930
Publication Date: 20161213
Grant Date: 20161213
Priority Date: 20140930
Inventors: MAG STEFAN C.
KRASS DEREK C.
MERZ NICHOLAS G.
JARVIS DANIEL W.
RAO MATTHEW P.
YAN VINCENT
NGO MICHAEL
DINH RICHARD HUNG MINH
JOHANNESSEN THOMAS
Assignee: APPLE INC
CPC Classifications: [{"code": "C25D11/022", "inventive": true, "first": true, "tree": "[]"}, {"code": "C25D11/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C65/7847", "inventive": false, "first": false, "tree": "[]"}, {"code": "C25D11/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K26/3293", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/022", "inventive": true, "first": true, "tree": "[]"}, {"code": "C25D11/022", "inventive": true, "first": true, "tree": "[]"}, {"code": "C25D11/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/26", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K2103/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C65/7847", "inventive": false, "first": false, "tree": "[]"}, {"code": "B23K2103/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "C25D11/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "B23K26/322", "inventive": true, "first": false, "tree": "[]"}, {"code": "B32B37/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/04", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/243", "inventive": true, "first": false, "tree": "[]"}, {"code": "C25D11/26", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 55583521