PATENT DOCUMENT

Publication Number: US-8988890-B2
Application Number: US-201213598308-A
Country: US
Kind Code: B2

Title: Component mounting structures with breakaway support tabs

Abstract:
Components may be mounted to printed circuit substrates using solder. A breakaway support tab may be detachably connected to a component and may help prevent the component from shifting or toppling over during reflow operations. The component and breakaway support tab may be formed from sheet metal. The interface that links the component to the breakaway support tab may be perforated or half sheared to allow the breakaway support tab to be easily separated from the component following reflow operations. The breakaway support tab may be fixed in place during reflow operations by mechanically coupling the breakaway support tab to a fixture or by mounting the breakaway support tab to an unused portion of a panel of printed circuit substrates. A breakaway support tab may be mechanically coupled between two components on a printed circuit substrate and may be used to maintain a distance between the components during reflow operations.

Claims:
What is claimed is: 
     
       1. Apparatus, comprising:
 a printed circuit substrate; 
 a component mounted to the printed circuit substrate using solder; 
 a breakaway support tab detachably connected to the component and configured to prevent the component from shifting with respect to the printed circuit substrate during solder reflow operations; and 
 a solder pad, wherein the component is mounted on the solder pad and wherein the breakaway support tab is configured to align the center of mass the component with the solder pad. 
 
     
     
       2. The apparatus defined in  claim 1  further comprising a perforated interface interposed between the component and the breakaway support tab. 
     
     
       3. The apparatus defined in  claim 1  further comprising a notch interposed between the component and the breakaway support tab. 
     
     
       4. The apparatus defined in  claim 1  wherein the component and the breakaway support tab each comprise sheet metal. 
     
     
       5. The apparatus defined in  claim 1  further comprising an additional component mounted to the printed circuit substrate using additional solder, wherein the breakaway support tab is detachably connected to the additional component and is configured to maintain a distance between the component and the additional component during solder reflow operations. 
     
     
       6. The apparatus defined in  claim 1  further comprising a fixture configured to receive a portion of the breakaway support tab and to hold the breakaway support tab in place with respect to the printed circuit substrate during reflow operations. 
     
     
       7. The apparatus defined in  claim 1  wherein the printed circuit substrate is a flexible printed circuit substrate. 
     
     
       8. The apparatus defined in  claim 1  wherein the component comprises an opening configured to receive an engagement member. 
     
     
       9. Apparatus, comprising:
 a panel having a plurality of printed circuit substrates interposed between unused portions; 
 a component mounted to a respective one of the printed circuit substrates in the plurality of printed circuit substrates; and 
 a support structure mounted to a respective one of the unused portions, wherein a perforated interface is interposed between the component and the support structure such that the support structure is detachably connected to the component and is configured to stabilize the component with respect to the respective one of the printed circuit substrates in the plurality of printed circuit substrates during solder reflow operations. 
 
     
     
       10. The apparatus defined in  claim 9  wherein the component and the support structure each comprise sheet metal. 
     
     
       11. The apparatus defined in  claim 9 , wherein the panel comprises polyimide. 
     
     
       12. The apparatus defined in  claim 9  further comprising a plurality of openings in the panel, wherein each opening in the plurality of openings at least partially surrounds an associated printed circuit substrate in the plurality of printed circuit substrates. 
     
     
       13. A method for mounting a component to a printed circuit substrate, comprising:
 attaching the component to a surface of the printed circuit substrate using solder paste; 
 conveying the printed circuit substrate into a reflow oven; 
 using a detachable support tab that is mechanically coupled to the component to stabilize the component with respect to the printed circuit substrate while the printed circuit substrate is in the reflow oven; wherein the component and the detachable support tab are formed from a single piece of sheet metal; and 
 detaching the detachable support tab from the component. 
 
     
     
       14. The method defined in  claim 13  further comprising:
 forming the component and the detachable support tab, wherein forming the component and the detachable support tab comprises perforating an interface that links the component to the detachable support tab. 
 
     
     
       15. The method defined in  claim 13  further comprising:
 forming the component and the detachable support tab, wherein forming the component and the detachable support tab comprises half shearing an interface that links the component to the detachable support tab. 
 
     
     
       16. The method defined in  claim 13  further comprising:
 removing the printed circuit substrate from the reflow oven, wherein detaching the detachable support tab from the component comprises detaching the detachable support tab from the component after removing the printed circuit substrate from the reflow oven. 
 
     
     
       17. The method defined in  claim 13  wherein detaching the detachable support tab from the component comprises breaking a perforated interface that links the component to the detachable support tab after conveying the printed circuit substrate into the reflow oven.

Description:
BACKGROUND 
     This relates to electronic components and, more particularly, to mounting electronic components onto substrates such as printed circuit substrates. 
     Components such as integrated circuits, attachment structures, stiffeners and other electronic devices and structures are typically mounted to printed circuit substrates using solder. In a typical arrangement, solder paste is printed onto conductive pads on the surface of the printed circuit substrate. A pick and place tool may then attach components to the substrate by placing components on the printed solder paste. Following placement of components on the substrate, the substrate may be conveyed into a reflow oven to convert the solder paste into solder connections. 
     In conventional arrangements, components on the printed circuit substrate shift during the reflow process as the solder melts. Components shifting during the reflow process can result in inaccurately placed components or can cause the components to topple over during reflow. Components with more complex shapes are sometimes soldered by hand after reflow, but this process often results in lower quality printed circuit arrangements and can adversely affect throughput. 
     It would therefore be desirable to be able to provide improved techniques for mounting components to printed circuits. 
     SUMMARY 
     Components may be mounted to printed circuit substrates using solder. A breakaway support tab may be detachably connected to a component and may be used to prevent the component from shifting with respect to the printed circuit substrate as solder melts during reflow operations. 
     Components and breakaway support tabs may be formed from sheet metal. An interface that links a component to a breakaway support tab may be perforated or half sheared to allow the breakaway support tab to be easily separated from the component following reflow operations. 
     A breakaway support tab may be mechanically coupled between two components on a printed circuit substrate and may be used to maintain a distance between the components during reflow operations. The breakaway support tab may be detachably connected to a first component at one end and detachably connected to a second component at a second end. Following reflow operations, the breakaway support tab may be detached from the components by severing the respective interfaces that link the components to the breakaway support tab. 
     A fixture may be used to hold the breakaway support tab in place during reflow operations. The fixture may include an engagement feature configured to receive a corresponding engagement feature on the breakaway support tab. By holding the breakaway support tab in place during reflow operations, the location of the component may remain fixed with respect to the printed circuit substrate during reflow operations. 
     Printed circuit substrates may be formed form a panel of printed circuit substrates. The panel may include multiple printed circuit substrates interposed between unused portions. Openings may be formed in the panel and may each partially surround an associated one of the printed circuit substrates. Components may be mounted to the panelized printed circuit substrates using solder and the panel may be conveyed into a reflow oven. 
     A breakaway tab may have a first portion detachably connected to a component on one of the printed circuit substrates and a second portion mounted to one of the unused portions of the panel. The breakaway tab may be used in stabilizing the component with respect the printed circuit substrate during reflow operations. Following reflow operations, the printed circuit substrates may be depanelized. The breakaway support tab may be separated from the component by severing or breaking a perforated or half-sheared interface that links the component to the breakaway support tab. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device such as a laptop computer with electronic device structures that may be assembled using threaded standoffs in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative electronic device such as a handheld electronic device with electronic device structures that may be assembled using threaded standoffs in accordance with an embodiment of the present invention. 
         FIG. 3  is a perspective view of an illustrative electronic device such as a tablet computer with electronic device structures that may be assembled using threaded standoffs in accordance with an embodiment of the present invention. 
         FIG. 4  is a perspective view of an illustrative component mounted to a printed circuit substrate using solder in accordance with an embodiment of the present invention. 
         FIG. 5  is a side view of the arrangement shown in  FIG. 4  in accordance with an embodiment of the present invention. 
         FIG. 6  is a perspective view of an illustrative breakaway support tab that is detachably connected to a component in accordance with an embodiment of the present invention. 
         FIG. 7  is a side view of an illustrative component that is mounted to a printed circuit substrate using solder and is detachably connected to a breakaway support tab in accordance with an embodiment of the present invention. 
         FIG. 8  is a side view of an illustrative component that is mounted to a printed circuit substrate using solder and is detachably connected to a breakaway support tab in accordance with an embodiment of the present invention. 
         FIG. 9  is a perspective view of an illustrative component that is mounted to a printed circuit substrate using solder and is detachably connected to a breakaway support tab held in place by a fixture in accordance with an embodiment of the present invention. 
         FIG. 10  is a top view of an illustrative panel of printed circuit substrates in which a breakaway support tab has a first portion detachably connected to a component and a second portion mounted to an unused portion of the panel in accordance with an embodiment of the present invention. 
         FIG. 11  is a perspective view of the arrangement shown in  FIG. 10  in accordance with an embodiment of the present invention. 
         FIG. 12  is a perspective view of an illustrative pair of components that are mechanically coupled together by a breakaway support tab in accordance with an embodiment of the present invention. 
         FIG. 13  is a top view of a component and a breakaway support tab that are linked by a perforated interface in accordance with an embodiment of the present invention. 
         FIG. 14  is a side view of a component and a breakaway support tab that are linked by a half sheared interface in accordance with an embodiment of the present invention. 
         FIG. 15  is a flow chart of illustrative steps involved in mounting a component to a printed circuit substrate using a breakaway support tab in accordance with an embodiment of the present invention. 
         FIG. 16  is a flow chart of illustrative steps involved in mounting components to panelized printed circuit substrates using breakaway support tabs in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Components such as stiffeners, clips, and other structures may be mounted to a printed circuit using solder. Solder paste may be printed on the printed circuit using a stencil. A surface mount tool such as a pick and place tool may be used to attach the components to the substrate by placing components on the printed solder paste. Following placement of the components on the substrate, the substrate may be conveyed into a reflow oven to convert the solder paste into solder connections. Components that are mounted to printed circuit substrates in this way are sometimes referred to as surface mount technology (SMT) components. 
     The shifting of components as solder melts during reflow may be minimized by forming components with one or more detachable support tabs. Detachable support tabs may be used to align the center of mass of a component with a solder pad on which the component is mounted, thereby providing the component with greater stability during reflow. A detachable support tab may have a first portion detachably connected to a component and second end held in place by a fixture or soldered to an unused portion of a panel of printed circuits. Detachable support tabs may also be used to maintain a precise distance between components throughout the mounting process. Following reflow operations, the detachable support tab may be severed from the desired part. 
     Illustrative electronic devices that may be provided with SMT components are shown in  FIGS. 1 ,  2 , and  3 .  FIG. 1  shows how electronic device  10  may have the shape of a laptop computer having upper housing  12 A and lower housing  12 B with components such as keyboard  16  and touchpad  18 . Assemblies such as printed circuit substrates having SMT components may be mounted within upper housing  12 A and/or lower housing  12 B. 
       FIG. 2  shows how electronic device  10  may be a handheld device such as a cellular telephone, music player, gaming device, navigation unit, or other compact device. In this type of configuration for device  10 , housing  12  may have opposing front and rear surfaces. Display  14  may mounted on a front face of housing  12 . Display  14  may, if desired, have a display cover layer or other exterior layer that includes openings for components such as button  36  and speaker port  38 . Assemblies such as printed circuit substrates having SMT components may be mounted within housing  12 . 
       FIG. 3  shows how electronic device  10  may be a tablet computer. In electronic device  10  of  FIG. 3 , housing  12  may have opposing planar front and rear surfaces. Display  14  may be mounted on the front surface of housing  12 . As shown in  FIG. 3 , display  14  may have a cover layer or other external layer with an opening to accommodate button  36 . 
     The configurations for device  10  shown in  FIGS. 1 ,  2 , and  3  are merely illustrative. In general, electronic device  10  may be 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. 
     Device  10  may have a housing enclosure such as housing  12 . Housing  12 , which is sometimes referred to as a case or enclosure, may be formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other composites, metal, aluminum, 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, welded standoffs, engagement structures, engagement member receiving structures, or other internal housing structures). 
     Device  10  may have one or more displays such as display  14 . Display  14  may be a liquid crystal display, an organic light-emitting diode (OLED) display, or other suitable display. Display  14  may include display pixels formed from light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), plasma cells, electronic ink elements, liquid crystal display (LCD) components, and/or other suitable display pixel structures. Display  14  may, if desired, include capacitive touch sensor electrodes for a capacitive touch sensor array or other touch sensor structures (i.e., display  14  may be a touch screen). 
     A perspective view of an illustrative assembly that may be mounted in device  10  is shown in  FIG. 4 . As shown in  FIG. 4 , assembly  100  may include a printed circuit substrate such as printed circuit substrate  22 . Printed circuit substrate  22  may include one or more layers of dielectric and one or more layers of conductor. Printed circuit  22  may, for example, be a flexible printed circuit formed from materials such as polyimide (sometimes referred to as a “flex circuit”), may be a rigid printed circuit board formed form a material such as fiberglass-filled epoxy (e.g., FR4), or may be formed from other suitable materials or combinations of these materials. 
     Components such as integrated circuits or other circuit components, batteries, cameras, compasses, wireless communications circuits, antennas, and other circuitry may be formed on or mounted to the surface of printed circuit substrate  22 . Printed circuit substrate  22  may also include one or more structural components such as structural component  24 . Structural components such as component  24  may include clips, stiffeners, connectors, attachment features, engagement members, and other structures. As examples, component  24  may be used in providing support for an acoustic module in device  10  or may provide a conductive path for tuning an antenna in device  10 . Component  24  may, if desired, include one or more openings for receiving an engagement member (e.g., component  24  may serve as a washer or other engagement member receiving structure). Component  24  may be formed from metal, plastic, glass, ceramic, other suitable materials, or combinations of these materials. Component  24  may, for example, be formed from sheet metal (e.g., sheet metal formed from aluminum, steel, tin, nickel, brass, copper, titanium, other suitable metals, etc.). 
     Components such as component  24  may be mounted to conductive pads on printed circuit  22  such as solder pad  26 . Solder pad  26  may be formed from conductive material such as tin, lead, gold plated copper, or other suitable metals. Prior to mounting components to printed circuit  22 , solder paste  28  may be applied to the surfaces of solder pads  26  on substrate  22  using a solder paste printing stencil. A pick and place tool may be used to mount components  24  on substrate  22  over solder pads  26  and solder paste  28 . 
     Solder connections may be formed between component  24  and solder pad  26  by reflowing solder paste structures in a reflow oven, by heating solder paste or solder balls using a localized heat source such as a heat bar (hot bar) or heat gun, or using other suitable solder reflow techniques. 
     If care is not taken, molten solder on which components are placed can cause components to shift or become unstable during reflow operations. Complex or odd-shaped components may run the risk of toppling over during reflow operations. For example, a component may have a center of mass which is offset from the solder pad on which the component is mounted, which can lead to instability during reflow. Detachable support tabs may be used to support a component during reflow operations. 
       FIG. 5  is a side view of assembly  100  showing how center of mass  30  of component  24  may be offset by a distance D from central portion  32  of solder pad  26 . To ensure that component  24  does not topple over in direction  34  during reflow operations, a detachable support tab may be attached to component  24  as component  24  undergoes the reflow process. Assembly  100  of  FIG. 5  may be a post-reflow assembly in which a detachable support tab has been detached from component  24 . 
       FIG. 6  is a perspective view of component  24  showing how component  24  may be formed with a detachable support structure such as breakaway support tab  40 . Support tab  40  may be a rigid but breakable structure that is detachably connected to component  24  at interface  42 . Support tab  40  may be formed from any suitable material. Support tab  40  may, for example, be formed from the same material as component  24  (e.g., a single piece of sheet metal may be used to form component  24  and detachable support tab  40 ). This is, however, merely illustrative. If desired, support tab  40  may be formed from a separate structure and/or a different material and may be detachably connected to component  24  during reflow operations. 
     Support tab  40  may provide component  24  with increased stability during reflow operations by adjusting the center of mass of component  24 . For example, support tab  40  (sometimes referred to as a balancing tab) may be used to align the center of mass of component  24  with the solder pad on which component  24  is mounted. Following reflow operations, support tab  40  may detached from component  24  by severing tab  40  at interface  42 . 
       FIG. 7  is a side view of reflow assembly  102  that includes component  24  and detachable support tab  40 . By mechanically coupling support tab  40  to component  24 , center of mass  40  of component  24  may be shifted towards central portion  32  of solder pad  26 . In the example of  FIG. 7 , center of mass  40  of component  24  is offset from central portion  32  by a distance P, which may be less than distance D of  FIG. 5  (e.g., the center of mass offset of reflow assembly  102  may be less than the center of mass offset of post-reflow assembly  100 ). This is, however, merely illustrative. If desired, balancing tab  40  may be configured such that the center of mass of component  24  is perfectly aligned with central portion  32  of solder pad  26 . 
     Following reflow operations, component  24  may be securely mounted to printed circuit substrate  22 . Balancing tab  40  may be severed at interface  42 , thereby leaving the desired component in a post-reflow assembly such as post-reflow assembly  100  of  FIGS. 4 and 5 . 
     In the example of  FIG. 7 , balancing tab  40  mirrors the shape of component  24  (e.g., balancing tab  40  and component  24  each have an L-like shape, together forming a U-like shape which is symmetric about axis  32 ). This is merely illustrative. In general, balancing tab  40  may have any suitable shape (e.g., an S-like shape, a C-like shape, a wave-like shape, a planar shape, etc.) 
       FIG. 8  is a side view of reflow assembly  104  in which balancing tab  40  is substantially planar. As shown in  FIG. 8 , balancing tab  40  may align center of mass  44  of component  24  with central portion  32  of solder pad  26 , thereby providing component  24  with increased stability during reflow. Following reflow operations, balancing tab  40  may be removed from component  24  by severing the connection at interface  42 . 
     In the example of  FIG. 8 , interface  42  at which balancing tab  40  is severed is located beyond edge  22 E of substrate  22  (e.g., such that interface  42  does not overlap substrate  22 ). This may ensure that solder does not come into contact with balancing tab  40  during reflow and that balancing tab  40  remains easily detachable. This is, however, merely illustrative. In general, interface  42  may be formed at any suitable location. For example, interface  42  may be formed at a location which overlaps substrate  22  (if desired). 
     In the example of  FIGS. 6 ,  7 , and  8 , detachable support tab  40  may be used to shift the center of mass of a component during reflow operations to provide the component with greater stability as solder melts. Detachable support tab  40  may also be used to maintain a component&#39;s precise position on a printed circuit substrate. An illustrative reflow assembly in which a detachable support tab is used to fix a component in a precise location with respect to a printed circuit substrate during reflow is shown in  FIG. 9 . 
     Assembly  106  of  FIG. 9  may include component  24  mounted on substrate  22  using solder  28 . In the example of  FIG. 9 , component  24  is provided with an engagement feature such as opening  48 . Opening  48  may be configured to receive a corresponding engagement feature or may be used for other suitable purposes. This is, however, merely illustrative. If desired, component  24  may be free of openings and/or may have other suitable shapes. 
     Component  24  may be provided with a support tab such as detachable support tab  40 . Detachable support tab  40  may be held in place by a fixture such as fixture  46 . For example, support tab  40  may include an engagement feature such as T-shaped end portion  40 T. Fixture  46  may have a corresponding engagement feature such as tab receiving opening  46 R. As shown in  FIG. 9 , opening  46 R in fixture  46  may receive T-shaped end portion  50 T of support tab  40 , thereby attaching support tab  40  to fixture  46 . This is, however, merely illustrative. If desired, other attachment mechanisms may be used to attach support tab  40  to fixture  46 . Fixture  46  may be formed from any suitable material (e.g., metal, plastic, glass, other suitable materials, combinations of these materials, etc.). 
     Assembly  106  may be conveyed into a reflow oven to convert solder paste  28  into a solder connection with component  24 . Because component  24  is attached to support tab  40 , which is fixed by fixture  46 , component  24  may remain in the same location with respect to substrate  22  during reflow. Following reflow operations, support tab  40  may be detached from component  24  by severing support tab  40  at interface  42 , thereby leaving the desired component (component  24 ) securely mounted to substrate  22 . 
     By mechanically coupling component  24  to a fixture such as fixture  46  during reflow operations, component  24  may be prevented from shifting during reflow as solder  28  melts. This type of placement precision may enhance the quality of a printed circuit assembly (e.g., by allowing components to be more densely populated on a substrate). 
     In the example of  FIG. 9 , component  24  is held in place by support tab  40 , which is in turn held in place by fixture  46 . This is merely illustrative. If desired, support tab  40  may be held in place by soldering a portion of support tab  40  to a fixed surface. For example, support tab  40  may be soldered to an unused portion of a substrate that passes through the reflow oven with substrate  22 . 
       FIG. 10  is a top view of an illustrative configuration in which support tab  40  is soldered to an unused portion of a substrate that passes through the reflow oven with substrate  22 . As shown in  FIG. 10 , assembly  108  may include a panel such as panel  50  that includes a cluster of printed circuits such as printed circuits  22 . Each printed circuit  22  may be partially surrounded by holes  52 . Holes  52  may allow printed circuits  22  to be easily depanelized (severed) from panel  50  after panel  50  has passed through a reflow oven. 
     Portions between substrates  22  such as portions  54  may be unused portions which are discarded or which are otherwise not used after substrates  22  are depanelized. As shown in  FIG. 10 , support tab  40  may have a first portion detachably connected to component  24  (at interface  42 ) and a second portion which is attached to unused portion  54  of panel  50 . As assembly  108  is passed through a reflow oven, support tab  40  may ensure that component  24  remains in the same location on printed circuit substrate  22  during the reflow process. Following reflow operations, substrate  22  may be depanelized and support tab  40  may be severed from component  24  at interface  42 . 
       FIG. 11  is a perspective view of assembly  108  showing how detachable support tab  40  may be mounted to unused portion  54  of panel  50 . As shown in  FIG. 11 , a solder pad such as solder pad  56  may be formed on unused surface  54  of panel  50 . End portion  40 A of support tab  40  may be attached to solder pad  56  using solder paste such as solder paste  58 , whereas end portion  40 B of support tab  40  may be detachably connected to component  24  at interface  42 . 
     Detachable support tab  40  may provide stability and support for component  24  during reflow operations and may prevent component  24  from shifting with respect to substrate  22  during reflow operations. Component  24  may, for example, have a relatively low amount of bonding area (i.e., may have a relatively small portion which is soldered to substrate  22 ), and may therefore benefit from the support provided by support tab  40  as panel  50  is conveyed into a reflow oven. Following reflow operations, substrate  22  may be depanelized by cutting or severing connecting portions  70  to separate substrate  22  from panel  50 . Once substrate  22  has been depanelized, support tab  40  may be severed from component  24  at interface  42 . 
     In another suitable embodiment, two or more components may be connected during reflow operations by a detachable support tab.  FIG. 12  is a perspective view of an illustrative reflow assembly in which component  24  and component  58  are mechanically coupled together by detachable support tab  40 . Components  24  and  58  may be any suitable type of component (e.g., clips, stiffeners, connectors, attachment features, engagement members, other structures, etc.). As shown in reflow assembly  110  of  FIG. 12 , component  24 , support tab  40 , and component  58  may be surface mounted to printed circuit substrate  22  as a single part. Component  24  may have a first portion such as portion  24 A mounted to solder pad  26  using solder paste  28 . Component  24  may have a second portion such as portion  24 B attached to support tab  40  at interface  42 . Component  58  may have a first portion such as portion  58 A mounted to solder pad  60  using solder paste  62 . Component  58  may have a second portion such as portion  58 B attached to support tab  40  at interface  64 . Support tab  40  may have a first portion such as portion  40 C attached to component  24  at interface  42  and a second portion such as portion  40 D attached to component  58  at interface  64 . 
     Component  24 , support tab  40 , and component  58  may be formed from a single structure (e.g., from a single piece of sheet metal). This is, however, merely illustrative. If desired, component  24 , support tab  40 , and component  58  may be formed from separate structures that are attached together at interfaces  42  and  64  and/or may be formed from different materials. 
     By mechanically coupling component  24  with component  58  using support tab  40 , a distance such as distance W may be maintained between components  24  and  58  during reflow operations (e.g., as solder paste  28  and  62  begins to melt). Additionally, in arrangements where component  24  and/or component  58  have relatively small bonding area, support tab  40  may be used in providing support and stability for components  24  and  58  during reflow. Following reflow operations, support tab  40  may be detached from components  24  and  58  by severing support tab  40  at interfaces  42  and  64 , thereby leaving components  24  and  58  on substrate  22  separated by distance W. With this type of arrangement, the precise distance between components may be determined prior to the surface mounting process and may be maintained throughout reflow operations. 
       FIG. 13  is a top view a portion of component  24  and detachable support tab  40  showing how support tab  40  may be attached to component  24  at interface  42 . As shown in  FIG. 13 , interface  42  that links component  24  with support tab  40  may be provided with openings such as openings  66 . Openings  66  (sometimes referred to as holes or perforations) may have any suitable size and may be formed along interface  42  using any suitable hole-forming process (e.g., perforating, punching, stamping, laser-cutting, etc.). Openings  66  may allow detachable support tab  40  to be easily torn or broken away from component  24  following reflow operations. For example, detachable support tab  40  may be detached from component  24  by severing support tab  40  along perforations  66 . 
       FIG. 14  is a side view of a portion of component  24  and detachable support tab  40  showing another suitable embodiment for providing support tab  40  with breakaway capabilities. As shown in  FIG. 14 , interface  42  that links component  24  with support tab  40  may be provided with a notch such as V-shaped notch  68 . Notch  68  may be formed by partially piercing through support tab  40  at interface  42  (sometimes referred to as half shearing). Notch  68  may allow detachable support tab  40  to be easily torn away from component  24  following reflow operations. For example, detachable support tab  40  may be detached from component  24  by severing support tab  40  along notch  68 . 
       FIG. 15  is a flow chart of illustrative steps involved in mounting a component to a printed circuit substrate using a detachable support tab such as detachable support tab  40 . 
     At step  200 , a component such as component  24  may be formed with a detachable support tab such as detachable support tab  40 . This may include, for example, forming component  24  and detachable support tab  40  from a single piece of sheet metal. Detachable support tab  40  may be provided with breakaway capabilities by perforating or half shearing the interface that links the component to the detachable support tab. 
     At step  202 , component  24  may be mounted to the surface of a printed circuit substrate such as printed circuit substrate  22  (e.g., a flexible printed circuit substrate, a rigid printed circuit board, or a rigid-flex printed circuit substrate). This may include forming solder pads on the surface of the printed circuit substrate, depositing solder paste on the solder pads, and attaching the component to the solder paste using a pick and place tool. 
     At step  204 , the reflow assembly that includes component  24  and detachable support tab  40  mounted on printed circuit substrate  22  may be conveyed into a reflow oven to convert the solder paste into solder connections. This is, however, merely illustrative. If desired, other techniques may be used to reflow solder on substrate  22  (e.g., using a localized heat source such as a heat bar or heat gun, using other suitable solder reflow techniques, etc.). Because component  24  is stabilized by detachable support tab  40 , component  24  may be prevented from shifting with respect to substrate  22  or from toppling over during reflow as solder melts. 
     At step  206 , substrate  22  may be removed from the reflow oven and detachable support tab  40  may be separated from component  24 , thereby leaving the desired component securely mounted in the desired location (as shown in  FIG. 4 , for example). This may include, for example, bending, breaking, or severing support tab  40  at interface  42  along perforations  66  ( FIG. 13 ) or notch  68  ( FIG. 14 ). 
       FIG. 16  is a flow chart of illustrative steps involved in mounting components to panelized printed circuit substrates using detachable support tabs such as detachable support tab  40 . 
     At step  300 , a panel such as panel  50  having multiple panelized printed circuit substrates  22  may be received. Each printed circuit substrate  22  in panel  50  may be interposed between unused space (e.g., unused space  54  of  FIG. 10 ). The unused space may be portions of panel  50  that do not form part of individual printed circuit substrates  22  in panel  50 . 
     At step  302 , a component such as component  24  having detachable support tab  40  maybe mounted to one of the panelized printed circuit substrates. This may include, for example, forming solder pads on the surface of the printed circuit substrate, depositing solder paste on the solder pads, and attaching the component to the solder paste using a pick and place tool. 
     At step  304 , detachable support tab  40  may be mounted to an unused portion of panel  50  (e.g., unused portion  54  adjacent to substrate  22  on which component  24  is mounted). This may include, for example, forming a solder pad on the unused surface of the panel, depositing solder paste on the solder pad, and attaching the detachable support tab to the solder paste using a pick and place tool. If desired, step  302  and step  304  may be performed simultaneously (e.g., a pick and place tool may be used to surface mount component  24  and support tab  40  simultaneously as a single part). 
     At step  306 , the panel of printed circuit substrates that includes components such as component  24  and support tab  40  may be conveyed into a reflow oven to convert the solder paste into solder connections. If desired, other techniques may be used to reflow solder on substrate  22  (e.g., using a localized heat source such as a heat bar or heat gun, using other suitable solder reflow techniques, etc.). Because component  24  is stabilized by detachable support tab  40 , component  24  may be prevented from shifting with respect to substrate  22  or from toppling over during reflow as solder melts. 
     At step  308 , printed circuit substrates  22  may be depanelized from panel  50 . This may include cutting or severing substrate  22  from panel  50  (e.g., by cutting trough or breaking away connecting portions  70  of  FIG. 11 ), thereby separating substrate  22  from panel  50 . 
     At step  310 , detachable support tab  40  may be separated from component  24 , thereby leaving the desired component securely mounted in the desired location). This may include, for example, bending, breaking, or severing support tab  40  at interface  42  along perforations  66  ( FIG. 13 ) or notch  68  ( FIG. 14 ). The example in which printed circuit substrates  22  are depanelized (step  308 ) before support tab  40  is severed (step  310 ) is merely illustrative. If desired, support tab  40  may be severed from component  24  before printed circuit substrate  22  is depanelized from panel  50 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20120829
Publication Date: 20150324
Grant Date: 20150324
Priority Date: 20120829
Inventors: WITTENBERG MICHAEL B.
KOLE JARED M.
COHEN SAWYER I.
MALEK SHAYAN
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K2201/0394", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/0394", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09063", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/4913", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/1031", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/0052", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/341", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2201/1034", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49144", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/1031", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/4913", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/0052", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/341", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2201/09063", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/1034", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49144", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02P70/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02P70/50", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 50187325