PATENT DOCUMENT

Publication Number: US-9680975-B2
Application Number: US-201314029330-A
Country: US
Kind Code: B2

Title: Electronic device with reworkable midplate attachment structures

Abstract:
An electronic device may be provided with a display mounted in a display frame assembly that includes a plastic structure overmolded over a display frame. A housing midplate may be used to provide the electronic device with mechanical rigidity and strength, and may also be used as a sensor plane. For sensor plane applications, accurate placement and assembly of the midplate in the housing can be critical. The housing midplate may be accurately assembled to the display frame using connections formed using welded tabs, welded and screwed nuts, overmolded plastic heat stake structures, or overmolded plastic structures and adhesive. Rework and repair operations may be performed by disconnecting connections such as welds using cutting equipment, by using solvent to dissolve adhesive, by unscrewing welded nuts, or by removing heat stake structures. Following rework or repair, a fresh midplate and associated components may be attached to the display frame.

Claims:
What is claimed is: 
     
       1. An electronic device, comprising:
 a housing; 
 a display; 
 a display frame that receives the display, wherein the display frame has first and second opposing sides; and 
 a midplate within the housing that is attached to the display frame with a weld, wherein the midplate extends behind the display from the first side of the display frame to the second side of the display frame. 
 
     
     
       2. The electronic device defined in  claim 1  wherein the midplate has two parallel tabs separated by a slot and wherein the weld is formed between one of the two parallel tabs and the display frame. 
     
     
       3. The electronic device defined in  claim 2  wherein the display frame has a display frame tab that is welded to the midplate by the weld. 
     
     
       4. The electronic device defined in  claim 3  further comprising plastic overmolded over the display frame. 
     
     
       5. The electronic device defined in  claim 4  wherein the plastic and the display frame form a display frame assembly that is attached to the display with adhesive. 
     
     
       6. The electronic device defined in  claim 1  wherein the midplate has a tab, wherein the display frame has two parallel tabs separated by a slot, and wherein the weld is formed between one of the two parallel tabs of the display frame and the tab of the midplate. 
     
     
       7. The electronic device defined in  claim 6  further comprising plastic overmolded over the display frame to form a display frame assembly to which the display is attached with adhesive. 
     
     
       8. An electronic device, comprising:
 a housing; 
 a display; 
 a display frame that receives the display; 
 a midplate within the housing that is attached to the display frame with a weld; 
 a screw; and 
 a nut that is attached to the display frame with the screw, wherein the weld is formed between the nut and the midplate. 
 
     
     
       9. The electronic device defined in  claim 8  wherein the display frame has a tab, wherein a hole is formed in the tab, and wherein the screw passes through the hole. 
     
     
       10. The electronic device defined in  claim 9  wherein the midplate has a tab and wherein the weld is formed between the nut and the tab of the midplate. 
     
     
       11. The electronic device defined in  claim 10  further comprising a plastic structure that is overmolded over the display frame to from a display frame assembly that is attached to the display with adhesive. 
     
     
       12. An electronic device, comprising:
 a housing; 
 a display; 
 a display frame that receives the display; 
 a midplate within the housing; and 
 a plastic structure overmolded onto a portion of the midplate, wherein midplate is attached to the display frame with the plastic structure. 
 
     
     
       13. The electronic device defined in  claim 12  further comprising adhesive that attaches the display frame to the plastic structure. 
     
     
       14. The electronic device defined in  claim 13  wherein the portion of the midplate onto which the plastic structure is overmolded is a prong. 
     
     
       15. The electronic device defined in  claim 12  wherein the plastic structure has a heat stake that is received within an opening in the display frame. 
     
     
       16. The electronic device defined in  claim 15  wherein the portion of the midplate onto which the plastic structure is overmolded is a prong and wherein the display frame has a tab in which the opening is formed. 
     
     
       17. A method, comprising:
 mounting a display in an electronic device display frame having first and second opposing sides; and 
 attaching a housing midplate to the display frame using a permanent connection, wherein the housing midplate extends behind the display from the first side of the electronic device display frame to the second side of the electronic device display frame. 
 
     
     
       18. The method defined in  claim 17  further comprising:
 removing the permanent connection during repair operations on an electronic device containing the electronic device display frame. 
 
     
     
       19. The method defined in  claim 18  wherein the permanent connection comprises a weld between a tab on the electronic device display frame and the housing midplate. 
     
     
       20. The method defined in  claim 19  wherein removing the permanent connection comprises cutting away a tip portion of the tab to remove the weld from the electronic device display frame, the method further comprising welding a replacement midplate to the tab after removing the weld.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to mounting structural components within an electronic device housing. 
     Electronic devices often include internal structures for providing added strength to device housings. For example, some cellular telephones include a planar internal metal structure to help stiffen the cellular telephone housing. Planar internal metal structures of this type are sometimes referred to as midplates. Midplates can be mounted within a housing using screws. A hole in a midplate may accommodate a screw that is used to fasten the midplate to a mating housing structure. When it is desired to rework or repair a device, screws can be unscrewed by a technician. Although screws allow for rework, reliance on holes and screws for proper alignment between the midplate and the mating housing structures can introduce alignment inaccuracies and movement of the midplate over the lifetime of a device. This can lead to performance issues for components that rely on accurate midplate placement. 
     It would therefore be desirable to be able to provide improved ways to mount structural components within an electronic device housing. 
     SUMMARY 
     An electronic device may be provided with a display. The display may be received within a display frame assembly that includes a plastic structure overmolded over a display frame. A housing midplate may be used to provide the electronic device with mechanical rigidity and strength, and may also be used as a sensor plane. For sensor plane applications, accurate placement and assembly of the midplate in the housing is critical. The housing midplate may be accurately assembled to the display frame using connections formed using welded tabs, welded and screwed nuts, overmolded plastic heat stake structures, or overmolded plastic structures and adhesive. 
     Rework and repair operations may be performed by removing permanent connections such as welds using cutting equipment, by using solvent to dissolve adhesive, by unscrewing welded nuts, by removing heat stake structures, or using other techniques. Following rework or repair, repaired structures may be reattached to the display frame assembly or a fresh midplate and new components may be attached to the display frame assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a handheld computing device in accordance with an embodiment. 
         FIG. 2  is a cross-sectional side view of an illustrative electronic device with a midplate in accordance with an embodiment. 
         FIG. 3  is an exploded perspective view of a display assembly and a midplate that may be joined to form a display module in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of a midplate member and associated display frame that are being jointed using equipment such as a laser welding tool in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of a portion of an electronic device in which a welded connection or other permanent connection between a midplate member and associated display frame is being trimmed off to permit rework of the electronic device in accordance with an embodiment. 
         FIG. 6  is a perspective view of an illustrative reworkable coupling arrangement based on welded nuts for coupling a midplate and a display frame in an electronic device in accordance with an embodiment. 
         FIG. 7  is a perspective view of an illustrative reworkable coupling arrangement based on heat stakes for coupling a midplate and a display frame in an electronic device in accordance with an embodiment. 
         FIG. 8  is a perspective view of an illustrative reworkable coupling arrangement based on adhesive for coupling a midplate and a display frame in an electronic device in accordance with an embodiment. 
         FIG. 9  is a perspective view of an illustrative reworkable coupling arrangement based on welds for coupling a midplate and a display frame in an electronic device in accordance with an embodiment. 
         FIG. 10A  is a perspective view of a portion of an illustrative display frame assembly in accordance with an embodiment. 
         FIG. 10B  is a perspective view of a portion of the illustrative display frame assembly of  FIG. 10A  being welded to a midplate in accordance with an embodiment. 
         FIG. 10C  is a perspective view of a portion of the illustrative display frame assembly and midplate of  FIG. 10B  during a weld trimming process to facilitate rework in accordance with an embodiment. 
         FIG. 11A  is a perspective view of a portion of an illustrative display frame assembly with a hole through which a screw is passed to attach a weldable nut in accordance with an embodiment. 
         FIG. 11B  is a perspective view of the display frame assembly and weldable nut of  FIG. 11A  being welded to a midplate in accordance with an embodiment. 
         FIG. 11C  is a perspective view of a portion of the illustrative display frame assembly and midplate of  FIG. 11B  illustrating how a screw may be removed to detach the weldable nut and midplate from the display frame assembly in accordance with an embodiment. 
         FIG. 12A  is a perspective view of a portion of an illustrative display frame assembly to which a weldable nut has been attached with a screw and that has been coupled to a midplate by welding the midplate to the weldable nut in accordance with an embodiment. 
         FIG. 12B  is a perspective view of the display frame assembly, weldable nut, and midplate of  FIG. 12A  showing how a screw may be removed from the weldable nut to remove the midplate for rework in accordance with an embodiment. 
         FIG. 12C  is a perspective view of a portion of the illustrative display frame assembly of  FIG. 12B  following rework operations in which a defective midplate has been replaced with a defect-free replacement midplate in accordance with an embodiment. 
         FIG. 13A  is a perspective view of a portion of an illustrative display frame with a pair of weldable tabs that has been coupled to a midplate by welding in accordance with an embodiment. 
         FIG. 13B  is a perspective view of the display frame assembly and midplate of  FIG. 13A  showing where a display frame tab may be cut so that the midplate can be removed during rework operations in accordance with an embodiment. 
         FIG. 13C  is a perspective view of a portion of the illustrative display frame assembly of  FIG. 13B  following rework operations in which a defective midplate has been replaced by a defect-free replacement midplate in accordance with an embodiment. 
         FIG. 14A  is a perspective view of a portion of an illustrative display frame with a pair of weldable tabs that has been coupled to a midplate by welding a first of the tabs to the midplate in accordance with an embodiment. 
         FIG. 14B  is a perspective view of the display frame assembly and midplate of  FIG. 14A  showing where the first display frame tab may be cut so that the midplate can be removed during rework operations in accordance with an embodiment. 
         FIG. 14C  is a perspective view of a portion of the illustrative display frame assembly of  FIG. 14B  following rework operations in which a defective midplate has been replaced by a defect-free replacement midplate by removing the first display frame tab and welding a second of the pair of weldable tabs to the midplate in accordance with an embodiment. 
         FIG. 15A  is a perspective view of a portion of an illustrative display frame with a weldable tab that has been welded to a midplate in accordance with an embodiment. 
         FIG. 15B  is a perspective view of the display frame assembly and midplate of  FIG. 15A  showing where the display frame tab may be cut so that the midplate can be removed during rework operations in accordance with an embodiment. 
         FIG. 15C  is a perspective view of a portion of the illustrative display frame assembly of  FIG. 15B  following rework operations in which a defective midplate has been replaced by a defect-free replacement midplate by removing a tip portion of the display frame tab and welding a lower portion of the display frame tab to the midplate in accordance with an embodiment. 
         FIG. 16  is a flow chart of illustrative steps involved attaching a midplate to structures in a device housing such as display assembly structures and illustrative steps involved in performing rework operations in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with housings. Components such as displays, sensors, buttons, batteries, and other electronic components may be mounted in a device housing. To enhance structural strength, it may be desirable to incorporate internal housing structures such as planar metal structures into an electronic device. For example, housing rigidity and strength may be enhanced by incorporating a metal midplate into an electronic device. The midplate may be a planar sheet metal structure that runs parallel to front and rear surfaces of the electronic device. The electronic device may be a handheld electronic device such as a cellular telephone or may be other electronic equipment. The midplate and housing structures to which the midplate is mounted may be configured to facilitate rework and repair. If, for example, a defective part is detected during device manufacturing that is associated with the midplate or that is blocked by the midplate, the midplate may be removed and the part repaired or replaced. The original midplate or a replacement midplate may then be installed in the device. 
     An illustrative electronic device of the type that may be provided with a display is shown in  FIG. 1 . An electronic device such as electronic device  10  of  FIG. 1  may be computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment. In the illustrative configuration of  FIG. 1 , device  10  is a portable device such as a cellular telephone, media player, tablet computer, or other portable computing device. Other configurations may be used for device  10  if desired. The example of  FIG. 1  is merely illustrative. 
     Device  10  may have one or more displays such as display  14  mounted in housing structures such as housing  12 . Housing  12  of device  10 , which is sometimes referred to as a case, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device  10  may be formed using a unibody construction in which most or all of housing  12  is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal frame elements or other internal housing structures). 
     Display  14  may be a touch sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display  14  may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components. 
     Display  14  for device  10  includes display pixels formed from liquid crystal display (LCD) components or other suitable display pixel structures such as organic light-emitting diode display pixels, electrophoretic display pixels, plasma display pixels, etc. 
     A display cover layer may cover the surface of display  14  or a display layer such as a color filter layer (e.g., a layer formed from a clear substrate covered with patterned color filter elements) or other portion of a display may be used as the outermost (or nearly outermost) layer in display  14 . The outermost display layer may be formed from a transparent glass sheet, a clear plastic layer, or other transparent member. If desired, openings may be formed in the outermost layer of display  14  to accommodate components such as button  16  and speaker port  18  of  FIG. 1  (as examples). Buttons, connector ports, and other structures may also be accommodated using openings in housing  12 . 
     A cross-sectional side view of electronic device  10  of  FIG. 1  taken along line  20  of  FIG. 1  and viewed in direction  22  of  FIG. 1  is shown in  FIG. 2 . As shown in  FIG. 2 , display  14  may include outer display layer  30  and inner display layers  32 . Outer display layer  30  of display  14  may be a layer of clear glass or plastic. For example, display layer  30  may be a display cover glass layer or other transparent display cover layer. Layers  32  may form a liquid crystal display, an organic light-emitting diode display, a plasma display, an electrophoretic display, or other display. For example, layers  32  may include liquid crystal display layers such as a layer of liquid crystal material interposed between a color filter layer and a thin-film transistor layer and sandwiched between opposing upper and lower polarizers. If desired, the color filter layer or thin-film transistor layer may be used in place of display cover layer  30 . Configurations for display  14  in which display  14  has a display cover layer are sometimes described herein as an example. Display layers  32  are sometimes referred to as forming a display module or display for device  10 . 
     Device  10  may include internal components  36  mounted on one or more substrates such as substrate  34 . Internal components  36  may include integrated circuits, sensors, switches, connectors, and other electronic components. Substrate  34  may be a printed circuit board or other substrate. For example, substrate  34  may be a rigid printed circuit board formed from a material such as fiberglass-filled epoxy or may be a flexible printed circuit board such as a flex circuit formed from a sheet of polyimide or a layer of other flexible polymer. 
     Display  14  (e.g., display cover layer  30  and/or display layers  32 ) may be mounted on a front face of device  10 . Housing portion  12 ′ may form a parallel rear housing wall. Housing portion  12 ′ may be formed as an integral portion of other portions of housing  12  (e.g., housing sidewalls) or the sidewalls and rear housing portion  12 ′ of housing  12  may be formed from separate members that are attached to each other using adhesive, fasteners, or other attachment techniques. 
     Structural support for device  10  may be provided by one or more internal housing structures such as midplate  38 . Midplate  38  may be a planar structure that lies in a plane parallel to the front and rear faces of device  10 . Midplate  38  may, for example, lie at a location that is between rear housing wall  12 ′ and display  14  (layers  30  and/or  32 ) on the front face of device  10 . Midplate  38  may be a plate or other planar structure formed from one or more sheet metal members that are optionally overmolded with plastic structures. The presence of midplate  38  may help provide device  10  with rigidity and strength. For example, the presence of midplate  38  may provide device  10  with resistance to undesired flexing (e.g., twisting, etc.). 
     If desired, components such as component  40  may be mounted on the upper surface of midplate  38  and/or may be mounted on the lower surface of midplate  38 . Component  40  may be a battery, a switch, an audio component such as a speaker driver or microphone, may be a vibrator, may be a connector, may be a camera, may be a light-emitting diode, may be a sensor (e.g., a capacitive touch sensor, a proximity sensor, an ambient light sensor, etc.), or may be another suitable electronic component. The successful operation of component  40  may benefit from accurate placement of component  40  in lateral dimensions X and Y and may also benefit from accurate placement of component  40  in vertical dimension Z. 
     In configurations in which components such as component  40  are supported by midplate  38 , accurate midplate placement may help ensure that the components will be located accurately with respect to the front and/or rear face of housing  12 . Component performance may be adversely affected by placement too close or far from other structures in device  10 . Accurate midplate placement within device  10  is therefore helpful for ensuring satisfactory operation of components such as component  40  in device  10 . Accurate midplate placement will also help ensure that nearby components such as antennas and other devices that are potentially affected by midplate placement will function properly. Midplate placement may also affect the way in which mechanical components in device  10  interact with each other. For example, inaccurate midplate placement may weaken the mechanical strength of device  10 . 
     Accurate midplate placement can be achieved by adjusting the position of midplate  38  within device  10  using computer-controlled positioners (or manually). Sensors such as a camera, light sensors, laser-based sensors, and other equipment for monitoring the position of midplate  38  relative to other structures in device  10  may be used in gathering information on the placement of midplate  38  in real time. Once a desired position has been achieved for midplate  38 , connections  42  (e.g., welds, screws, other fasteners, solder, adhesive, heat stakes, or other attachment mechanisms) may be used to secure midplate  38  within device  10 . 
     In the example of  FIG. 2 , display  14  is mounted in display frame assembly  48  using adhesive  50  to form a display assembly. Frame assembly  48  may be formed from plastic, metal, fiber composite material, or other materials. For example, frame assembly  48  may be formed from plastic frame structure  46  that have been overmolded onto metal frame  44 . Connections  42  may be used to attach midplate  38  to metal frame  44  in frame assembly  48 . Connections  42  may include welds, screws or other fasteners, solder, heat stakes, adhesive, or other attachment mechanisms. Welding equipment or other assembly equipment may be used to form connections  42  after sensor equipment determines that midplate  38  has been positioned in a desired location within device  10  (i.e., a desired position with respect to frame  44  in the display assembly). 
     During manufacturing, tests may be performed on fully and partially assembled devices  10 . If a faulty component or other defect is detected in device  10 , device  10  can be scrapped or reworked. In some situations, device  10  may experience an unexpected component failure in the field and may need to be repaired. During rework and repair operations such as these, it may be desirable to remove midplate  38  from housing  12 . For example, it may be difficult or impossible to repair a component such as component  40  while component  40  and midplate  38  are installed within housing  12  because midplate  38  blocks component  40 . Once the repair is complete, however, midplate  38  or a replacement midplate will once again need to be accurately installed within device  10 . 
     The process of temporarily removing midplate  38  from device  10  and housing  12  to facilitate rework and repair typically involves disconnecting connections  42 . This may be accomplished by cutting (e.g., using a laser, a mechanical cutting device, etc.), by unscrewing screws or otherwise detaching detachable fasteners, using solvent to dissolve adhesive, using heat, or by otherwise detaching midplate  38  from frame  44  and other structures associated with device  10 . As an example, a welded portion of midplate  38  and frame  44  may be removed using a cutter or a screw-based connection between midplate  38  and frame  44  may be unscrewed. Following repair or replacement of faulty structures (e.g., faulty components such as component  40 ), the removed midplate or a replacement midplate may be reinstalled within device  10 . Accurate placement of the midplate following rework or repair operations may be ensured using position sensors and real time control of the position of midplate  38  using computer-controlled positioners. New connections  42  may then be formed to secure the midplate  38 . 
     Midplate  38  may, in general, be attached to any portion of device  10  such as inner portions of housing walls  12 , portions of a front or rear surface of housing  12 , frame structures or brackets attached to housing sidewalls or front or rear housing surfaces, or other structural elements (housing structures) in device  10 . Configurations in which midplate  38  is attached to frame  44  of display frame assembly  48  are sometimes described herein as an example. 
     Midplate  38  and frame assembly  48  may have features that facilitate attachment of midplate  38  and frame assembly  48 . For example, midplate  38  and frame assembly  48  may have mating tabs or other protrusions. This type of arrangement is shown in the perspective view of illustrative midplate  38  and frame assembly  48  of  FIG. 3 . In the illustrative configuration of  FIG. 3 , midplate  38  has protrusions such as bent tabs  38 T. Display frame assembly  48  includes metal frame  44  and overmolded plastic structures  46 . As indicated by dashed lines  44 ′, metal frame  44  may have a rectangular ring shape with a central rectangular opening. Overmolded plastic structures  46  may have a rectangular ring shape. Protrusions such as tabs  44 T of frame  44  may be configured to mate with corresponding tabs  38 T on midplate  38 . Overmolded plastic structures  46  may cover the rectangular ring portion of frame  44 , while allowing tabs  44 T to protrude. 
     In the arrangement shown in  FIG. 3 , display  14  has been received within the central rectangular opening within frame assembly  48  to form a display assembly. During assembly operations, the display assembly may be positioned so that tabs  44 T of frame  44  mate with tabs  38 T of midplate  38 . A camera, laser-based sensor, and/or other sensors may be used to ensure that the display assembly and midplate  38  are positioned accurately with respect to each other. Connections  42  ( FIG. 2 ) may then be formed using welding or other attachment techniques. The resulting structure, which may sometimes be referred to as a display module, includes frame  44  and plastic structures  46  of frame assembly  48 , includes display  14 , and includes midplate  38 . The display module may then be installed within housing  12  of device  10 . In this example, the position of midplate  38  is accurately determined with respect to display  14 , so components such as component  40  that are mounted on midplate  38  will have an accurately defined separation from nearby components such as display  14 . This may help ensure that device  10  operates properly (e.g., in configurations in which the performance of component  40  can be affected by the separation between component  40  and display  14 ). Display  14  is mounted on the front surface of device  10 , so the accurate placement of midplate  38  results in accurate placement of component  40  relative to the front face of device  10  and can also help control the placement of component  40  and midplate  38  relative to structures in device  10  that are coupled to display  14  such as housing  12 . 
     Connections  42  may be formed by welding equipment, soldering equipment, equipment for installing fasteners such as screws, equipment for applying and curing adhesive, equipment for forming heat stakes, or other tools for attaching structures together in device  10 . Consider, as an example, the system of  FIG. 4 . In the illustrative system of  FIG. 4 , a sensor such as sensor  51  is being used to monitor the relative positions of two structures that are being attached to each other such as tab  44 T of frame  44  and tab  38 T of midplate  38 . Sensor  51  may be a digital image sensor (e.g., a camera), may be a photodiode, may be a laser-based optical sensor, may be switch or other mechanical position sensor, may include acoustic range-finding devices, may include magnetic sensors, contact sensors, resistive sensors, or other sensors for detecting and measuring the position of objects. Computer-controlled positioning equipment may be used to adjust the relative position between frame  44  and midplate  38 . For example, computer-controlled positioner  56  may be used to adjust the position of frame  44  and computer-controlled positioner  58  may be used to adjust the position of midplate  38 . Sensor  51  may be used to provide information on the positions of frame  44  and/or midplate  38  during operation of the computer-controlled positioning equipment. 
     Once frame  44  and midplate  38  have been positioned as desired (i.e., once the desired relative position of midplate  38  with respect to frame  44  has been achieved), connection forming equipment  52  may be used to form connections  42 . Connection forming equipment  52  may be equipment for screwing a screw or for forming an attachment using a rivet, may be adhesive dispensing equipment for dispensing and curing adhesive, may be equipment for forming a solder joint, may be equipment for forming a heat stake, or may be equipment for forming a welded connection. For example, equipment  52  may be a laser for producing laser light  54  that welds frame  44  to midplate  38 . Other techniques for welding or otherwise attaching first and second respective metal structures in device  10  together may be used if desired (e.g., friction welding, arc welding, gas welding, etc.). 
     During subsequent testing or during use by a user in the field, faults may be detected in components such as component  40  that require rework or repair. To disconnect connection  42 , it may be desirable to cut away a portion of the structures that were welded together (as an example).  FIG. 5  is a cross-sectional side view of the attached structures of  FIG. 4  during an illustrative weld removal process. In the example of  FIG. 5 , midplate  38  was previously connected to frame  44  of display frame assembly  48  using connection  42 . Connection may be a weld or other permanent connection (i.e., a connection of the type that cannot be easily reversed as would be the case when unscrewing a screw). Because connection  42  (in this example) is an irreversible connection, connection removal equipment  60  is being used to cut off the portion of the structures that are connected using connection  42 . 
     Connection removal equipment  60  may include a cutter such as cutter  70 . Cutter  70  may have one or more blades or other structures for cutting metal (as an example). Connection removal equipment  60  may include a clamp formed from clamp members such as clamp member  62  and clamp member  66 . When it is desired to remove connection  42 , equipment  60  may use computer-controlled positioners to move clamp member  62  in direction  64  and to move clamp member  66  in direction  68 . By moving clamp members  62  and  64  together in this way and thereby closing the clamp, equipment  60  may grip tab  44 T of frame  44  and tab  38 T of midplate  38 . While tab  44 T and tab  38 T are being held in position by equipment  60 , equipment  60  may use a computer-controlled positioner to move cutter  70  in direction  72 , thereby forming cut  74  through tab  44 T and tab  38 T. This cuts away tip portion  76  of tab  44 T and tab  38 T, so that connection  42  (i.e., the weld between frame  44  and midplate  38 ) may be removed. Once cut  74  has been formed and the portion of the display module that contains weld  42  has been removed (and once all other such welds  42  on the other tabs have been likewise removed), midplate  38  will be unrestrained by welds  42  and will be free to move relative to frame  44 . This allows midplate  38  to be removed from frame assembly  48  and the other structures in the display module. 
     Reworkable and repairable device structures may be based on welds that can be cut away from midplate  38 , may be based on solder joints that can be reworked by application of heat, may be based on screws and other removable fasteners, may be based on adhesive joints, may be based on heat stake connections, or may be based on other types of connections  42 .  FIGS. 6, 7, 8, and 9  show illustrative connections  42  that may be formed between midplate  38  and frame  44 . The configurations of  FIGS. 6, 7, 8, and 9  allow midplate  38  to be accurately located relative to frame  44  (e.g., using sensors and computer-controlled positioners) before connections  42  are formed. 
     In the example of  FIG. 6 , connection  42  has been formed from a welded nut. Nut  82  may be, for example, a metal nut that is welded to midplate  38  using weld  42 ′. During assembly, screw  80  may be screwed into a threaded opening in nut  82 , thereby attaching nut  82  to tab  44 T on frame  44  in frame assembly  48 . Following attachment of nut  82 , sensor equipment  51  and positioning equipment such as computer-controlled positioners  56  and  58  ( FIG. 4 ) may be used to accurately position midplate  38  relative to display frame assembly  48  and tab  44 T of frame  44 . When midplate  38  has been positioned as desired, welding equipment  52  ( FIG. 4 ) may be used to form weld  42 ′ between nut  82  and tab  38 T of midplate  38 . To rework this type of connection in the case of a non-functioning midplate  38 , screw  80  can be unscrewed and midplate  38  (and its attached nut  82 ) may be removed. With this rework functioning display frame assembly  48  is saved. A new fresh nut  82  is screwed to the tab  44 T, and a new fresh midplate  38  is welded to the nut. 
     In the example of  FIG. 7 , connection  42  has been formed using a heat stake arrangement. Plastic heat stake structure  84  is overmolded over a prong (tab) of midplate  38 . Structure  84  may have protruding heat stakes  86 . Tab  44 T of frame  44  in frame assembly  48  has openings such as circular holes that mate with the protruding heat stakes  86 . The openings are preferably larger in diameter than the diameter of the heat stakes, allowing movement between midplate  38  and frame assembly  48  before the heat stake connections are formed. The heat stakes initially have narrow (unflared) ends that are inserted through the holes in tab  44 T. Following insertion of the unflared ends of heat stakes  86 , sensor equipment  51  and positioning equipment such as computer-controlled positioners  56  and  58  ( FIG. 4 ) may be used to accurately position midplate  38  relative to display assembly  48  and tab  44 T of frame  44 . When midplate  38  has been positioned as desired, a heated metal bar or other heat source may be used to flare the ends of heat stakes  86 , thereby attaching midplate  38  to frame  44  in a desired position. To rework connection  42  of  FIG. 7 , heat stakes  86  may be cut away using a blade, using additional heat application, using machining equipment, or using other cutting or plastic removal equipment. A new midplate  38  with a correspondingly new overmolded heat stake structure  84  may then be attached to frame assembly  48 . 
       FIG. 8  is a perspective view of an illustrative connection  42  that has been formed using adhesive. As shown in  FIG. 8 , overmolded plastic structure  90  may be overmolded on top of a bent tab portion of midplate  38 . Adhesive  92  may then be used to attach structure  90  and attached midplate  38  to tab  44 T of frame  44 . Adhesive  92  may be a liquid adhesive such as ultraviolet light cured epoxy (as an example). Plastic structure  90  may be transparent to ultraviolet light (and potentially visible light). During assembly operations, uncured adhesive  92  may be placed between overmolded plastic structure  90  and tab  44 T. Sensor equipment  51  and positioning equipment such as computer-controlled positioners  56  and  58  ( FIG. 4 ) may then be used to accurately position midplate  38  relative to tab  44 T of frame  44 . When midplate  38  has been positioned as desired, an ultraviolet light source may be used to shine ultraviolet light through structure  90  onto adhesive  92 , thereby curing adhesive  92  and attaching midplate  38  to frame  44 . If desired, heat may be applied to cure adhesive  92  in addition to or instead of applying ultraviolet light. Solvents may be applied to adhesive  92  or cutting techniques or other mechanical techniques may be used to break connection  42  for rework or repair. 
       FIG. 9  is a perspective view of midplate  28  and frame assembly  48  in which connection  42  has been formed by welding tab  44 T to tab  38 T as described in connection with  FIG. 4 . Rework and repair operations may be facilitated by cutting away connection  42  as described in connection with  FIG. 5 . 
       FIGS. 10A, 10B, and 10C  illustrate the process of forming and removing a connection such as a weld. As shown in  FIG. 10A , frame assembly  48  is initially formed by overmolding plastic frame material  46  over frame  44  so that frame tab  44 T protrudes outwards from material  46 . As shown in  FIG. 10B , midplate  38  may then be accurately positioned relative to frame  44  by adjusting the location of midplate  38  in dimensions such as vertical dimension  100  (and, if desired, horizontally) before forming weld  42 . When rework or repair is required, weld  42  can be cut away (see, e.g., cut-away weld  42 - 1  of  FIG. 10C ) and, following rework or repair, a replacement weld  42  can be formed (see, e.g., replacement weld  42 - 2  of  FIG. 10C ). 
       FIGS. 11A, 11B, and 11C  illustrate the process of forming and removing a connection based on a welded nut (e.g., a configuration of the type shown in  FIG. 6 ). As shown in  FIG. 11A , frame assembly  48  is initially formed by overmolding plastic frame material  46  over frame  44  so that frame tab  44 T protrudes outwards from material  46 . Nut  82  may then be attached to frame tab  44 T using screw  80 . As shown in  FIG. 11B , midplate  38  may then be accurately positioned relative to frame  44  by moving midplate  38  vertically along dimension  112  (and, if desired, horizontally) using computer-controlled positioners such as positioners  56  and  58  of  FIG. 4 . After alignment, weld  42 ′ between tab  38 T of midplate  38  and nut  82  on frame tab  44 T may be formed (e.g., using welding equipment  52  of  FIG. 4 ). Because nut  82  is already attached to frame  44  when weld  42 ′ is formed, the use of a screw as part of the connection does not introduce uncertainty into the accuracy of the connection. If rework or repair is desired, screw  80  may be unscrewed from nut  82  as shown in  FIG. 11C . 
       FIGS. 12A, 12B, and 12C  show how a nut-based configuration for connection  42  may be reworked. Initially, connection  42  of  FIG. 12A  is formed by screwing nut  82  to tab  44 T. Following accurate alignment between midplate  38  and nut  82  (and therefore alignment between midplate  38  and frame  44 ), midplate  38 T is welded to nut  82 . When rework or repair is desired, screw  80  is removed from nut  82  so that nut  82  and midplate  38  can be removed ( FIG. 12B ). Following rework or repair operations, a new nut  82 ′ may be attached to tab  44 T and a new midplate  38  may be aligned and welded to nut  82 ′ as shown in  FIG. 12C . Original nut  82  is attached to original midplate  38  by welds  42 ′ and is therefore discarded when the original midplate is discarded, but a fresh nut  82  and a fresh midplate  38  can be attached to frame  44  once rework or repair operations are complete. 
       FIGS. 13A, 13B, and 13C  show how a weld-based configuration for connection  42  may be reworked. In the illustrative arrangement of  FIGS. 13A, 13B, and 13C , midplate  38  has two parallel tabs  38 T- 1  and  38 T- 2  and frame  44  has two corresponding parallel tabs  44 T- 2  and  44 T- 2 . The parallel midplate tabs are separated by slot  120  and the parallel frame tabs are separated by slot  120 . After placing midplate  38  in a desired position with respect to frame  44 , weld  42 F of  FIG. 13A  is used to weld tab  44 T- 1  to tab  38 T- 1  and thereby accurately secure midplate  38  to frame  44 . When it is desired to perform rework or repair operations, the tips of tab  44 - 1  and welded tab  38 T- 1  may be cut away along cut line  74 , as shown in  FIG. 13B . Cutting equipment such as the equipment of  FIG. 5  may be used to remove the undesired connection between frame  44  and midplate  38 . As shown in  FIG. 13C , after component  40  on midplate  38  has been repaired or after other desired rework or repair operations have been completed, midplate  38  can once again be aligned with respect to frame  44  and welded to frame  44  using weld  42 S on spare tabs  44 T- 2  and  38 T- 2 . The presence of the slots between the tabs allows for clearance at the end of the cutting tool used to form cut  74  and provides a smooth, burr-less edge tab along the side after rework. 
     With the illustrative configuration of  FIGS. 14A, 14B, and 14C , a new midplate is used when performing rework or repair operations. Initially, after midplate  38  has been aligned with respect to frame  44 , weld  42 X is used to weld tab  44 T- 1  to tab  38 T on midplate  38  as shown in  FIG. 14A . When it is desired to perform rework or repair operations, the weld between tab  44 T- 1  and tab  38 T can be removed by cutting along cut line  74  of  FIG. 14B  using cutting equipment of the type shown in  FIG. 5 . Following desired rework or repair operations, a new midplate  38  may be aligned with respect to frame  44 . New weld  42 Q of  FIG. 14C  may then be used to attach frame tab  44 T- 2  to tab  38 T of midplate  38 .  FIGS. 14A, 14B, and 14C  show how midplate  38  may be provided with a recessed portion behind tab  38 T- 1  such as relief  121 . In the absence of relief  121 , there would be a potential for cutting operations along cut  74  (e.g., laser cutting operations) to re-weld midplate  38  to the remaining portion of tab  44 T- 1 . By spacing tab  44 T- 1  and midplate  38  away from each other using relief  121 , a cutting tool such as a laser may be used to cut off the frame tab without risk of re-welding the frame tab to the midplate. 
       FIGS. 15A, 15B, and 15C  illustrate another approach for attaching midplate  38  to frame  44 . After aligning midplate  38  with respect to frame  44 , weld  42 N of  FIG. 15A  may be used to attach frame tab  44 T to midplate tab  38 T.  FIG. 15B  shows how weld  42 N may be cut away along cut line  74  (e.g., using cutting equipment of the type shown in  FIG. 5 ) when it is desired to perform rework or repair operations. Not all of tab  44 T is cut away, so the lower portions of tab  44 T remains for subsequent welding.  FIG. 15C  shows how a fresh midplate  38  may be attached to the remaining portion of tab  44 T after rework or repair operations. As shown in  FIG. 15C , new weld  42 P may be formed at the portion of tab  44 T that was not cut away during the operations of  FIG. 15B  (i.e., a portion of tab  44 T that was not removed when the cut along cut line  74  was formed). If desired, the original midplate may be welded to the portion of tab  44 T that remains (e.g., using the lower portion of original midplate tab  38 T). 
     Illustrative operations in forming electronic devices that have connections  42  between midplates  38  and frames  44  or other pairs of aligned internal housing structures in housing  12  (e.g., any other electronic device structures that include a first member such as a first metal member that is aligned and welded to a second member such as a second metal member) are shown in the flow chart of  FIG. 16 . The operations of steps  200  of  FIG. 16  may be used to create electronic device  10 . The operations of step  202  involved performing rework or repair operations on device  10 . 
     At step  204 , frame assembly  48  may be formed by molding plastic structures  46  onto metal frame  44  or forming other frame assembly structures. Frame assembly  48  (i.e., molded plastic structures and metal frame  44 ) may have a rectangular opening. The opening in frame assembly  48  may be configured to receive a component such as display  14 . Tabs  44  and other structures for facilitating attachment of midplate  38  to frame assembly  48  may be included on frame  44 . 
     At step  206 , a display assembly may be formed by mounting display  14  in frame assembly  48 . Adhesive  50  or other attachment mechanisms may be used in mounting display  14  in frame assembly  48 . 
     At step  208 , midplate  38  may be positioned at a desired location relative to frame  44  and the other portions of the display assembly. Computer-controlled positioners such as positioners  56  and  58  of  FIG. 4  may be used in aligning midplate  38  and frame  22 . Sensors such as a camera, laser-based position sensors, or other sensors  51  may be used to provide the computer-controlled positioners with real-time feedback so that midplate  38  and frame  22  may be positioned accurately with respect to each other. Once a desired alignment has been achieved between midplate  38  and the display assembly (i.e., once midplate  38  and frame  44  have been aligned), welding equipment or other equipment for forming connections  42  between frame  44  and midplate  38  may be used to form connections  42  that attach midplate  38  to frame  44 , thereby forming a display module. 
     The display module and other components of device  10  may be assembled into device housing  12  at step  210  to form device  10 . Computer-controlled assembly equipment and/or manual assembly techniques may be used in installing the display module in device housing  12 . 
     Following assembly of device  10 , device  10  may be tested. Test results acquired during manufacturing may reveal whether device  10  is functioning properly. An end user of device  10  may also determine whether device  10  is functioning properly when using device  10  in the field. If a defect is detected during testing or by a user in the field, device  10  can be reworked or repaired using the operations of steps  202 . 
     At step  212 , the display module that was formed at step  208  may be removed from housing  12  of device  10 . Rework or repair operations (e.g., rework or repair to fix a faulty component  40  on midplate  38  or other rework or repair operations) may be facilitated by removing midplate  38  from the display assembly at step  214 . Midplate  38  may be removed from the display assembly by forming cut lines such as cut lines  74  to cut away welds, by removing screws such as screw  80 , or by otherwise disconnecting connections  42  to release midplate  38  from frame  44 . 
     At step  216 , a repaired or new midplate (and any associated repaired or fresh components such as component  40 ) may be attached to frame  44 . For example, new welds may be formed, screws  80  and welds may be used to form a connection with a new nut, adhesive may be used in forming a connection, new heat stake connections may be formed, etc. Attaching the repaired or new midplate creates a defect free display module for device  10 . The defect free display module may be assembled into housing  12  to form a repaired version of device  10  at step  218 . 
     The alignment of a midplate and display frame and associated rework and repair operations have been described as an example. In general, any housing structures or other structures in electronic device  10  (e.g., any pair of metal structures or other structures) can be attached using connections  42  and can be likewise reworked or repaired. 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20130917
Publication Date: 20170613
Grant Date: 20170613
Priority Date: 20130917
Inventors: FILIZ SINAN
Comer Richard M.
TEIL ROMAIN A.
COHEN SAWYER I.
MARTISAUSKAS STEVEN J.
Assignee: APPLE INC
CPC Classifications: [{"code": "Y10T29/49826", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49718", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0266", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49718", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0266", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F1/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49826", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1637", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49826", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49718", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0266", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 52667777