PATENT DOCUMENT

Publication Number: US-8905793-B2
Application Number: US-201213607554-A
Country: US
Kind Code: B2

Title: Contacts for an electrical connector

Abstract:
An improved electronic contact assembly for electrical connectors is disclosed. A plurality of elongated metallic contacts may be formed, each having one or more protrusions that enable precision alignment within a connector. A plurality of the contacts may be insert-molded in a dielectric frame which may have alignment tabs, resilient alignment bosses, alignment posts and crushable combs, all enabling precise alignment of contacts within a connector.

Claims:
What is claimed is: 
     
       1. An electrical connector contact comprising:
 an elongate top contact plate comprising a substantially planar contact surface defined by a contact surface perimeter, the contact surface disposed above a substantially parallel lower surface having a perimeter that is larger than the contact surface perimeter; 
 an elongate bottom contact plate bonded at a substantially planar top surface to the lower surface of the top contact plate, and the bottom contact plate including at least two protrusions spaced apart along and extending from a bottom surface of the bottom contact plate away from the top contact plate. 
 
     
     
       2. The electrical connector contact set forth in  claim 1  wherein the bottom contact plate further comprises a recess portion disposed in the bottom surface. 
     
     
       3. The electrical connector contact set forth in  claim 2  wherein the bottom contact plate has a perimeter substantially equal to the perimeter of the lower portion of the top contact plate. 
     
     
       4. The electrical connector contact set forth in  claim 2  wherein the bottom contact has a perimeter of the top surface that is less than a perimeter of the bottom surface. 
     
     
       5. The electrical connector contact set forth in  claim 2  further comprising a recess portion disposed between the two protrusions. 
     
     
       6. A leadframe for use in an electrical connector contact, the leadframe comprising:
 a first leadframe with an elongate top contact plate comprising a substantially planar contact surface defined by a contact surface perimeter, the contact surface disposed above a substantially parallel lower surface having a perimeter that is larger than the contact surface perimeter; 
 a second leadframe with an elongate bottom contact plate bonded at a substantially planar top surface to the lower surface of the top contact plate, and the bottom contact plate including at least two protrusions spaced apart along and extending from a bottom surface of the bottom contact plate away from the top contact plate. 
 
     
     
       7. An electrical connector contact comprising:
 an elongate top contact plate comprising a substantially planar contact surface defined by a contact surface perimeter, the contact surface disposed above a substantially planar lower surface, the top contact plate comprising plated stainless steel; 
 an elongate bottom contact plate bonded at a substantially planar top surface to the lower surface of the top contact plate, bottom contact plate including at least two protrusions spaced apart along and extending from a bottom surface of the bottom contact plate away from the top contact plate, the bottom contact plate comprising a plated copper alloy. 
 
     
     
       8. The electrical connector set forth in  claim 7  wherein at least one of the top contact plate or bottom contact plate includes a perimeter that is larger than the contact surface perimeter forming a ridge around the contact surface. 
     
     
       9. The electrical contact set forth in  claim 7  wherein the top contact comprises an outer gold plating layer formed over a multilayer nickel plating layer. 
     
     
       10. The electrical contact set forth in  claim 9  wherein the bottom contact comprises an outer gold plating layer formed over a nickel plating layer.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to electrical connectors and in particular to electrical contact assemblies for electrical connectors. A wide variety of electronic devices are available for consumers today. Many of these devices have connectors that that facilitate communication with and/or charging of a corresponding device. These connectors often interface with other connectors through cables that are used to connect devices to one another. Sometimes, connectors are used without a cable to directly connect the device to another device, such as a charging station or a sound system. 
     As smart-phones, media players and other electronic devices become more compact, a limiting factor on the size of a particular device may be one or more of the connectors incorporated into the device. As an example, receptacle connectors are sometimes positioned on one or more of the side surfaces of portable media devices. The thickness of such portable media devices may be limited by the thickness of the receptacle connector or connectors incorporated into the device. Smaller and thinner receptacle connectors may allow the portable media device to be designed smaller. Since such receptacle connectors typically include contacts positioned within an insertion cavity that is sized to hold a corresponding plug connector, there is a desire to have the mating plug connector smaller and thinner as well. Some plug connectors, such as a standard USB 2.0 connector, include a metal shield that surrounds the plug connector contacts forming a cavity in which the contacts are positioned. The shield may provide some level of protection against electrical interference but adds to the overall thickness of the portion of the plug connector that is inserted into the receptacle. 
     New connectors that such as the external contact connector just described as well as other connectors, may require new features and/or changes to commonly used connector components to be manufactured to more precise tolerances associated with the smaller size and to withstand the rigors of everyday use over multiple thousands of use cycles. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the invention pertain to connect contacts, methods of manufacturing such contacts, a contact assembly and methods of manufacturing a connector using the contact assembly among other things. While the techniques of the invention can be used in a variety of different connectors, some embodiments of the invention are particularly useful for connectors that include contacts that positioned at an external surface of a plug connector and are thus not positioned within a cavity or surrounded by a metal or other type of shield as done in some prior art connectors. The lack of such a shield enables plug connectors according to certain embodiments of the invention to be thinner than had a shell been included and makes certain embodiments of the invention particularly useful in the manufacture of especially small or thin connectors. 
     Some embodiments relate to the formation of electronic contacts that may have one or more protrusions from a bottom surface and a substantially planar top contact surface. In some embodiments the contacts are unitary, and in other embodiments the contacts are comprised of a top plate and a bottom plate that are bonded together. In some embodiments the two plates are processed in a reel-to-reel leadframe blanking, forming and plating process and are laser welded together. The top plate and the bottom plate may have a ledge disposed on their periphery. Some embodiments of the bottom plate have a localized region of reduced thickness to improve the laser welding process. 
     Some embodiments of the invention relate to a contact assembly formed from a plurality of electronic contacts retained within a unitary dielectric frame. The contact assembly may be soldered to a PCB within a connector. In some embodiments the plurality of electronic contacts are precisely positioned in X, Y and Z dimensions by an insert-molding process that forms the dielectric frame. The dielectric frame may hold the contacts in precise X, Y and Z alignment during subsequent processing. Further, the dielectric frame may comprise alignment tabs, resilient alignment bosses, alignment posts and crushable combs that may work in conjunction with precision assembly tools to precisely position the top surface of the plurality of contacts within a connector. Further, in some embodiments, precise vertical positioning of the contact assembly within the connector may require solder bumps on the PCB and protrusions from the bottom of the electronic contacts to accommodate manufacturing tolerances. 
     Some embodiments of the invention relate to connectors that employ a contact assembly attached to a PCB, as discussed above, and are subsequently over molded with a dielectric material. One or more ledges features may be formed on the periphery of the electronic contacts to lock the contacts into the over mold material and secure them within the connector. 
     To better understand the nature and advantages of the present invention, reference should be made to the following description and the accompanying figures. It is to be understood, however, that each of the figures is provided for the purpose of illustration only and is not intended as a definition of the limits of the scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram that illustrates an example of a connector plug with external contacts. 
         FIG. 2A  is a diagram that illustrates a top perspective view of an electrical contact in accordance with an embodiment of the invention. 
         FIG. 2B  is a diagram that illustrates a bottom perspective view of an electrical contact in accordance with an embodiment of the invention. 
         FIG. 3A  is a diagram that illustrates a top perspective view of a bottom contact plate in accordance with an embodiment of the invention. 
         FIG. 3B  is a diagram that illustrates a bottom perspective view of a bottom contact plate in accordance with an embodiment of the invention. 
         FIG. 3C  is a diagram that illustrates a top perspective view of a bottom contact plate in accordance with an embodiment of the invention. 
         FIG. 4A  is a diagram that illustrates a top perspective view of a top contact plate in accordance with an embodiment of the invention. 
         FIG. 4B  is a diagram that illustrates a bottom perspective view of a top contact plate in accordance with an embodiment of the invention. 
         FIG. 5  is a process by which a contact assembly and a connector in accordance with an embodiment of the invention can be manufactured. 
         FIG. 6A  is a diagram that illustrates a reel-to-reel manufacturing system in accordance with an embodiment of the invention. 
         FIG. 6B  is a diagram that illustrates a reel-to-reel manufacturing system in accordance with an embodiment of the invention. 
         FIG. 7A  is a diagram that illustrates a representative portion of a top contact leadframe in accordance with an embodiment of the invention. 
         FIG. 7B  is a diagram that illustrates a representative portion of a top contact leadframe in accordance with an embodiment of the invention. 
         FIG. 8A  is a diagram that illustrates a representative portion of a bottom contact leadframe in accordance with an embodiment of the invention. 
         FIG. 8B  is a diagram that illustrates a representative portion of a bottom contact leadframe in accordance with an embodiment of the invention. 
         FIG. 9A  is a diagram that illustrates a representative portion of a bottom contact leadframe disposed on top of a representative portion of a top contact leadframe in accordance with an embodiment of the invention. 
         FIG. 9B  is a diagram that illustrates a representative portion of a bottom contact leadframe disposed on top of a representative portion of a top contact leadframe in accordance with an embodiment of the invention. 
         FIG. 10A  is a diagram that illustrates an insert-molding manufacturing system in accordance with an embodiment of the invention. 
         FIG. 10B  is a diagram that illustrates an insert-molding manufacturing system in accordance with an embodiment of the invention. 
         FIG. 11A  is a diagram that illustrates a representative portion of a bottom contact leadframe disposed on top of a representative portion of a top contact leadframe after insert-molding in accordance with an embodiment of the invention. 
         FIG. 11B  is a diagram that illustrates a representative portion of a bottom contact leadframe disposed on top of a representative portion of a top contact leadframe after insert-molding in accordance with an embodiment of the invention. 
         FIG. 12A  is a diagram that illustrates top perspective view of a contact assembly in accordance with an embodiment of the invention. 
         FIG. 12B  is a diagram that illustrates bottom plan view of a contact assembly in accordance with an embodiment of the invention. 
         FIG. 12C  is a diagram that illustrates side view of a contact assembly in accordance with an embodiment of the invention. 
         FIG. 13  is a diagram that illustrates an example of a connector plug with a contact assembly. 
         FIG. 14A  is a diagram that illustrates a hot bar soldering system in accordance with an embodiment of the invention. 
         FIG. 14B  is a diagram that illustrates a hot bar soldering system in accordance with an embodiment of the invention. 
         FIG. 14C  is a diagram that illustrates an example of a contact assembly assembled to a connector in accordance with an embodiment of the invention. 
         FIG. 15  is a process by which a contact assembly may be assembled to a connector in accordance with an embodiment of the invention. 
         FIG. 16  is a diagram that illustrates an example of a connector plug with external contacts in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Certain embodiments of the present invention relate to electrical contacts employed in electronic connectors. While the present invention can be useful to produce electrical contacts for a wide variety of connectors, some embodiments of the invention are particularly useful for producing contacts for connectors that are especially small, as described in more detail below. Embodiments of the invention may enable electronic contacts, in especially small connectors, to be precisely positioned, resulting in increased reliability and improved performance of electronic connectors. 
       FIG. 1  is a simplified perspective view of an exemplary plug connector  100  that may benefit from embodiments of the invention Plug connector  100  includes a connector tab  140  that is sized to be inserted into a cavity in a corresponding receptacle connector (not shown). Tab  140  includes a metal ground ring  160  that surrounds a contact assembly  130 . Contact assembly  130  may contain a plurality of external elongated electrical contacts  120 ( 1 ) . . .  120 ( 8 ) retained in a dielectric frame (not shown). This particular embodiment has eight electrical contacts, however other embodiments may have more or less electrical contacts. Connector  100  further comprises a connector body  110  and a cable bundle  150 . 
       FIGS. 2A and 2B  show top and bottom perspective views, respectively, of an exemplary elongated electrical contact  120 ( 1 ) employed in plug connector  100 . Electrical contact  120 ( 1 ) may be comprised of two plates, a top contact plate  205  and a bottom contact plate  207  bonded together at interface  206 . However, in some embodiments contact  120 ( 1 ) may be a substantially unitary structure. In one embodiment the overall height of the electrical contact is less than 1.5 mm, and in another embodiment between 0.75 mm and 0.25 mm. In one embodiment the overall width of the electronic contact is less than 1.0 mm, and in another embodiment between 0.75 mm and 0.25 mm. Also, in one embodiment, electronic contact  120 ( 1 ) is at least three times as long as it is wide and in another embodiment it is at least 5 times as long as wide. 
       FIGS. 3A and 3B  depict top and bottom perspective views of bottom contact plate  207 , respectively. Bottom contact plate  207  may have a substantially planar top surface  301  with one or more cavities  206   a ,  206   b . Bottom contact plate  207  may also have a substantially planar bottom surface  320  that may be substantially parallel with top surface  301 . Bottom surface  320  may have one or more protrusions  302   a ,  302   b  that extend from the bottom surface to a distal end  310   a ,  310   b . Protrusions  302   a ,  302   b  may be useful for soldering contact  102 ( 1 ) in an alignment within a connector such that a top surface of contact  120 ( 1 ) is coplanar with the top surfaces of contacts  120 ( 2 ) . . .  120 ( 8 ), as described in more detail below. Protrusions may have openings  315   a ,  315   b  that extend through the width of each protrusion. Bottom surface  320  may also have one or more recess portions  325  that result in a localized region of reduced thickness. Recess portion  325  may have one or more adjacent walls  330 . 
       FIG. 3C  depicts a top perspective view of an alternative embodiment of a bottom contact plate  350 . Bottom contact plate  350  may have a substantially planar top surface  351  with one or more cavities  376   a ,  376   b . Bottom contact plate  351  may also have a substantially planar bottom surface  370  that may be substantially parallel with top surface  351 . Top contact plate  350  may further have a lower surface  370  that has a perimeter that is greater than the perimeter of top surface  351 . The difference in perimeters may result in the formation of an annular ledge  385  disposed around the perimeter of the bottom contact plate. Bottom surface  370  may have one or more protrusions  352   a ,  352   b  that extend from the bottom surface to a distal end  360   a ,  360   b . Protrusions  352   a ,  352   b  may be useful for aligning contact  102 ( 1 ) in a connector, which will be described in more detail below. Protrusions may have openings  365   a ,  365   b  that extend through the width of each protrusion. Bottom surface  370  may be substantially similar to bottom surface  320  of bottom contact plate  207  depicted in  FIG. 3B . Further, bottom contact plate  350  may have one or more recess portions  325  (see  FIG. 3B ) that result in a localized region of reduced thickness. Recess portion  325  may have one or more adjacent walls  330  (see  FIG. 3B ). 
     In some embodiments bottom contact plates  207 ,  350  may be made from copper or a copper alloy like phosphor-bronze, for example. In other embodiments a different conductive material may be used. In some embodiments the bottom contact plate may be plated with one or more metals. In one embodiment the bottom contact plate may be first plated with one or more layers of nickel and may be subsequently plated with gold. 
       FIGS. 4A and 4B  depict top and bottom perspective views, respectively, of top contact plate  205 . Top contact plate  205  may have a substantially planar contact surface  401  that intimately and physically interfaces with an electrical contact in a mating receptacle connector (not shown). Top contact plate  205  may further have a lower portion  410  that has a perimeter  435  that is greater than contact surface perimeter  425 . The difference in perimeters  425  and  435  may result in the formation of an annular ledge  415  disposed around the perimeter of the top contact plate. Top contact plate  205  may have a substantially planar lower surface  420  that may be substantially parallel with contact surface  401 . The lower portion  410  may have a tie bar attachment region  440 . In some embodiments, top contact plate  205  may be made from copper or a copper alloy like phosphor-bronze, for example. In one embodiment the top contact is made from stainless steel. In other embodiments a different conductive material is used. In some embodiments the top contact plate may be plated with one or more metals. In one embodiment the top contact plate may be first plated with nickel and may be subsequently plated with gold. In another embodiment, the top contact plate may be plated with a multi-layer nickel underplate comprising a leveling nickel layer that is applied to the contact plate material, a subsequent layer of sulfumate nickel over the leveling nickel, and a layer of high-phosphorous nickel over the sulfumate nickel that may be subsequently plated with gold. Further details regarding methods and processes of multi-layer nickel underplating may be found in U.S. patent application Ser. No. 13/250,920, which is herein incorporated by reference in its entirety. 
     Reference is now made to  FIGS. 5-12  to illustrate an exemplary manufacturing process for one embodiment of contacts  120 , contact assembly  130  and connector  100  (see  FIG. 1 ).  FIG. 5  is a flow chart illustrating the general steps associated with the manufacture and assembly of contact assembly  130  and its integration into exemplary connector  100  (see  FIG. 1 ).  FIGS. 6-12  depict electrical contacts  120 ( 1 ) . . .  120 ( 8 ), contact assembly  130 , and connector  100  at various stages of manufacture. These processes illustrate the manufacturing process of one particular embodiment and it is understood that numerous other manufacturing processes may be employed without departing from the invention. 
     Now referring to  FIGS. 6A and 6B , the manufacture of electrical contacts  120 ( 1 ) . . .  120 ( 8 ) may be initiated, employing an exemplary reel-to-reel manufacturing process ( FIG. 5 , steps  510 - 550 ;  FIGS. 6-9 ).  FIG. 6A  depicts an exemplary reel-to-reel stamping or forming process for manufacturing metallic components attached to a leadframe. A de-spooling reel  605  may contain a length of raw leadframe material  615 . Raw leadframe material  615  may be any type of metal, including alloys. In one embodiment the raw leadframe material is an alloy of phosphor-bronze and is less than one mm thick. The de-spooling reel may rotate in a counter-clockwise direction and allow raw leadframe material  615  to enter one or more sets of die  640 ,  645 . In one embodiment, die  640  is stationary and die  645  travels in up and down cycles repeatedly. With each down cycle, die set  640 ,  645  may perform a blanking operation in which portions of raw leadframe material  615  are removed. With each up cycle, additional raw leadframe material  615  may be advanced into die set  640 ,  645 . This cycle may repeat many times per minute. Processed leadframe material  620  may exit the die set and be wound upon a re-spooling reel  610 . Because of the cyclical nature of the die set, the blanked features may be repeated patterns separated by a pitch  635 . Thus, the processed leadframe material  620  may be illustrated by a representative section  625 . 
     The reel-to-reel manufacturing process depicted in  FIG. 6A  may also be used to perform a forming operation. In a forming operation, instead of die set  640 ,  645  removing material from raw leadframe material  615 , features may be formed in the leadframe material. Some embodiments may use a multi-stage progressive die operation that has multiple die stages including blanking and forming operations. Some embodiments may employ single stage die operations while other embodiments may replace the blanking operation with a chemical etching process. Myriad equivalent blanking and forming processes may be employed without departing from the invention. 
     An early step of assembly may involve blanking and forming raw leadframe material into one or more top contact plates  205  (see  FIG. 4A ) with a reel-to-to reel manufacturing process similar to that illustrated in  FIG. 6A , ( FIG. 5 , steps  510 ,  520 ;  FIGS. 7A-7B ).  FIG. 7A  illustrates a representative section  701  of a blanked and formed leadframe used to manufacture top contact plate  205  (see  FIG. 4A ), for one embodiment. A carrier  705  may hold a subcarrier  710  to which a plurality of top contact plates  205  may be attached. Region  725  is illustrated in greater detail in  FIG. 7B  which shows that top contact plates  205  may remain attached to subcarrier  710  with tie bars  730  such that they can be wound on a re-spooling reel  610  (see  FIG. 6A ). 
     Another early step of assembly, which may be done concurrent with, before or after steps  510  and  520 , may involve blanking and forming raw leadframe material into one or more bottom contact plates  207  (see  FIG. 3A ) with a reel-to-to reel process similar to that illustrated in  FIG. 6A , ( FIG. 5 , steps  511 ,  521 ;  FIGS. 8A-8B ).  FIG. 8A  illustrates a representative section  801  of a blanked and formed leadframe used to manufacture bottom contact plate  207 , for one embodiment. A carrier  805  may be attached to a plurality of bottom contact plates  207 . Region  825  is illustrated in greater detail in  FIG. 8B  which shows that bottom contact plates  207  may remain attached to carrier  805  with tie bars  830  such that they can be wound on a re-spooling reel  610  (see  FIG. 6A ). 
     After the top contacts and bottom contacts are formed, they may be cleaned and plated while still attached to the leadframe with a reel-to-to reel process similar to that illustrated in  FIG. 6B , ( FIG. 5 , steps  530 ,  531 ;  FIGS. 7A ,  8 A). A reel-to-reel manufacturing process, as depicted in  FIG. 6B , may be employed for cleaning and plating operations. A de-spooling reel  655  may contain a length of blanked and formed leadframe material  665 . The de-spooling reel may rotate in a counter-clockwise direction and allow blanked and formed leadframe material  665  to enter one or more cleaning and plating baths  690 . The cleaned and plated leadframe material  670  may exit the cleaning and plating baths and be wound upon a re-spooling reel  660 . In one embodiment the blanked and formed leadframe material  665  may go through three washing processes, a nickel plating process and a gold plating process. Myriad cleaning and plating processes may be used, including selective plating, without departing from the invention. Referring now to the flowchart in  FIG. 5 , in step  530  top contact leadframe  701  (see  FIG. 7 ) may be plated using a reel-to-reel process. The bottom contact leadframe  801  (see  FIG. 8 ) may also be plated using a reel-to-reel process (step  531 ). Leadframes  701 ,  801  may be plated with the same or with different processes. 
     The next step of assembly may involve aligning bottom contact leadframe  801  over top contact leadframe  701  ( FIG. 5 , step  540 ;  FIGS. 9A-9B ). Leadframes  701  and  801  may be aligned such that top surface  301  (see  FIG. 3A ) of bottom contact  207  physically touches and is aligned on lower surface  420  (see  FIG. 4B ) of top contact  205 . In some embodiments the alignment process is performed with an automated system that incorporates computer-aided vision.  FIG. 9A-9B  depict leadframes  701 ,  801  on top of one another with bottom contact carrier  805  removed for clarity. 
     The next step of assembly may involve bonding bottom contact plate  207  to top contact plate  205 , forming elongated electrical contacts similar to  120 ( 1 ) depicted in  FIG. 2A  ( FIG. 5 , step  550 ;  FIGS. 9A-9B ) at each position where individual top and bottom contacts are mated. Region  925  of  FIG. 9A  is illustrated in greater detail in  FIG. 9B . In one embodiment, a laser welder may be used to perform the bonding operation. More specifically, in  FIG. 9B , a laser beam may be focused on recess portion  325  of bottom contact plate  207  such that the beam rapidly heats a localized portion of the bottom contact plate material near, or above its melting temperature, fusing the bottom contact plate to the top contact plate. In some embodiments, recess portion  325  may have a thinner cross-section than other portions of bottom contact  207 . The thinner cross-section may enable faster heating from the laser and improved welding. Further, some embodiments of bottom contact plate  207  may have one or more walls  330  adjacent to recess portion  325 . Walls  330  may serve the function of minimizing the deformation of bottom contact plate  207  during the bonding process. In some embodiments, bottom contact plate leadframe carrier  805  (see  FIG. 8A ) may be removed and bonded electrical contacts  120 ( 1 ) remain attached to top contact plate leadframe carrier  705  by tie bars  730 . In one embodiment, bottom contact plate leadframe carrier  805  may be removed by breaking tie bars  830  (see  FIG. 8B ) attached to bottom contact plates  207  with the aid of V-notches formed in the tie bars. In another embodiment, a laser may sever the tie bar connection. Myriad methods can be used to sever the tie bars without departing from the invention. 
     The next step of assembly may involve insert-molding a dielectric plastic material around one or more contacts  120 ( 1 ) . . .  120 ( 8 ) ( FIG. 5 , step  560 ;  FIGS. 6A ,  10 - 12 C). Insert-molding may be accomplished with a system that looks and functions similar to the reel-to-reel blanking and forming machine illustrated in  FIG. 6A . In one embodiment, die  640  is stationary and die  645  travels in up and down cycles repeatedly. With each down cycle, die set  640 ,  645  may perform an insert-molding operation around contacts  120 ( 1 ) . . .  120 ( 8 ) attached to leadframe carrier  705  (see  FIG. 9A ). With each up cycle, additional leadframe material may be advanced into die set  640 ,  645 . This cycle may repeat several times per minute. 
       FIGS. 10A and 10B  depict a simplified cross-section of die set  640 ,  645  and contacts  120 ( 1 ) . . .  120 ( 8 ) as employed in one embodiment. When the die set is in the open position as depicted in  FIG. 10A , the contacts may be held in place by carrier  705  (see  FIG. 9A ) and are aligned with die set  640 ,  645 . Upper die  645  may have close-out surfaces  1005  that seal against ledge  415  of top contact plate  205  (see  FIG. 4A ) on contacts  120 ( 1 ) . . .  120 ( 8 ). Lower die  640  may have close-out surfaces  1011  that seal against bottom surface  320  of bottom contact plate  207  (see  FIG. 3B ) on contacts  120 ( 1 ) . . .  120 ( 8 ). Lower die  640  may also have one or more comb formation recesses  1020 . 
       FIG. 10B  depicts die set  640 ,  645  in the closed position and after mold material  1050  has been injected. Upper die  645  may have clearance features  1030  such that the upper die only contacts ledge  415  of contacts  120 ( 1 ) . . .  120 ( 8 ) and not contact surface  401 . Lower die  640  may also have clearance features  1055  such that the lower die only contacts bottom surface  320  of contacts  120 ( 1 ) . . .  120 ( 8 ) and not protrusions  302   a ,  302   b . Upper die  645  may have close-out surfaces  1005  that may be precision machined such that all ledges  415  of the plurality of contacts  120 ( 1 ) . . .  120 ( 8 ) are forced to be substantially coplanar and precisely positioned in planar X and Y dimensions. In some embodiments, contacts  120 ( 1 ) . . .  120 ( 8 ) may be precisely manufactured such that when ledges  415  are substantially coplanar it forces contact surfaces  401  of the plurality of contacts to also be substantially coplanar. More specifically, in some embodiments, the insert-mold dies  640 ,  645  can position contact surfaces  401  to be within plus/minus 0.03 mm. In some embodiments contact surfaces can be within plus/minus 0.025 mm. In further embodiments, contact surfaces can be within plus/minus 0.02 mm, or less. 
     Once die set  640 ,  645  is in the closed position, a dielectric insert-molding material  1050  may be injected from one or more ports as illustrated by arrow  1060 . The dielectric material may be in a semi-liquid state and may fill all the voids between contacts  120 ( 1 ) . . .  120 ( 8 ) and any recesses in the die, such as comb recess  1020 . In some embodiments the dielectric material may be polypropylene, while in other embodiments the dielectric material may be a liquid crystal polymer that may be partially filled with glass fiber. The injected dielectric material may then be cooled to at least partially solidify it such that die set  640 ,  645  may be opened and injected material  1050  will retain its shape. One or more ejector pins (not shown) may force the solidified dielectric material, along with contacts  120 ( 1 ) . . .  120 ( 8 ), out of the die set.  FIGS. 11A and 11B  depict one embodiment of an insert-molded leadframe after it exits the die set.  FIG. 11A  illustrates representative leadframe section  1101  with an insert-molded contact assembly  130  held to carrier  705  by top contact plate tie bars  730 .  FIG. 11B  shows a more detailed top perspective view of contact assembly  130  with contacts  120 ( 1 ) . . .  120 ( 8 ) held together by a dielectric frame  1125  formed by injected dielectric material  1050 . 
     The next step of assembly may involve singulating contact assembly  130  from carrier  705 , (step  570 ,  FIGS. 12A-12C ). In some embodiments, the singulation process may be performed in the final stage of the insert-molding die. In alternative embodiments the insert-molded leadframe may then be reeled onto a re-spooling reel  610  (see  FIG. 6A ) and the singulation process may be performed in a machine similar to that illustrated in  FIG. 6A . In other embodiments the insert-molded leadframe material may be cut into sections and the sections may be employed in subsequent manufacturing processes.  FIG. 12A  shows a top perspective view of singulated contact assembly  130 .  FIG. 12B  shows a planar bottom view and  FIG. 12C  shows a side view. Once carrier  705  (see  FIG. 11A ) has been removed, dielectric frame  1125  may maintain the plurality of contacts  120 ( 1 ) . . .  120 ( 8 ) in precise X, Y and Z alignment with one another throughout subsequent processes. 
     Each contact assembly  130  may include a molded frame  1125 . One embodiment has eight contacts  120 ( 1 ) . . .  120 ( 8 ) that are insert-molded and secured by frame  1125 . Frame  1125  may be equipped with one or more alignment posts  1220  that protrude from a bottom surface of the dielectric frame. Alignment posts  1220  may be tapered and may have a beveled distal end. In some embodiments, the dielectric frame may have two, four or more alignment tabs  1210  disposed on the perimeter of the frame. Some embodiments may also have resilient alignment bosses  1215  disposed on either end of contact assembly  130 . Further, the dielectric frame may have one or more crushable combs  1225  that protrude from the bottom surface of the contact assembly  130 . In one embodiment, at least four crushable combs  1225  are formed on the bottom surface of assembly  130 . 
     The next step of assembly may involve integrating contact assembly  130  into an exemplary connector such as connector  100  (see  FIG. 1 ), ( FIG. 5 , step  580 ;  FIGS. 13-16 ). Referring now to  FIG. 13 , one or more contact assemblies  130  may be integrated into electrical connector  100 . In some embodiments a hot bar soldering process may be employed to precisely position contact assembly  130  in window  1305  of connector  100 . Contact assembly  130  may be affixed to a PCB  1310  residing in window  1305 . Further, a substantially flat surface  1320  may be machined or ground into ground ring  160  and may be used as a substantially flat alignment surface for contact assembly  130 , as further illustrated below. As mentioned above, some embodiments of contact assembly  130  are particularly useful for producing contacts for connectors that are especially small. Embodiments of the invention may enable electronic contacts, for particularly small connectors, to be precisely positioned, resulting in increased reliability and improved performance. Some of the features that may enable precise positioning of contact assembly  130  may be better understood by illustrating the contact assembly integration process for one embodiment. 
     The contact assembly integration process for one embodiment is illustrated in  FIGS. 14A and 14B . The detailed steps of the process are depicted in the flow chart in  FIG. 15 . The first step of the assembly process may comprise placing connector  100  in a fixture to hold the components in place ( FIG. 15 , step  1500 ;  FIG. 13 ). The next step of assembly may comprise positioning contact assembly  130  in window  1305  of ground ring  160  ( FIG. 15 , step  1510 ;  FIGS. 14A ,  14 B). Alignment posts  1220  of contact assembly  130  may be engaged with guide holes  1515  in PCB  1310 . Contact assembly alignment tabs  1210  (see  FIG. 12A ) may precisely position contact assembly  130  in window  1305  (see  FIG. 13 ). Crushable combs  1225  may be in physical contact with PCB  1310 . 
     The next step of assembly may comprise using a hot bar tool  1505  to assemble contact assembly  130  to PCB  1310  ( FIG. 15 , steps  1520 - 1580 ;  FIGS. 14A ,  14 B). Prior to assembly, one or more solder bumps  1535  may be disposed on PCB  1310 . The next step of assembly may comprise heating hot bar tool  1505  above the melting temperature of solder bumps  1535  (step  1520 ). For example, if solder bumps  1535  are composed of a tin/silver/copper alloy comprised of approximately three percent silver, one-half percent copper with the remainder tin, the hot bar tool may be heated above  221  degrees centigrade. The higher the temperature of the hot bar tool, the faster the solder may reflow. 
     In step  1530 , the hot bar tool may travel down, in the direction of arrow  1530 , towards contact assembly  130  until it physically touches top surface  401  of contacts  120 ( 1 ) . . .  120 ( 8 ). In step  1540 , hot bar tool  1505  may push contact assembly  130  further in the direction of arrow  1530 , partially deforming crushable combs  1225  against PCB  1310 . The crushable combs may be designed specifically for this purpose and may impart a controlled amount of force resisting movement of contact assembly  130  in the direction of arrow  1530 . Alignment tabs  1210  and alignment posts  1220  may keep the contact assembly precisely centered in window  1305  (see  FIG. 13 ) during the assembly process. Step  1510  of hot bar tool  1505  may be precision formed to maintain top surface  401  of contacts  120 ( 1 ) . . .  120 ( 8 ) co-planar and at a controlled height during the attachment process. Further, dielectric frame  1125  (see  FIG. 12A ) may maintain the contacts in precise X, Y and Z alignment relative to one another during the attachment process. 
     In step  1540 , the contact assembly may be further pushed in the direction of the arrow until contact protrusions  302   a ,  302   b  come into contact with solder bumps  1535 . Hot bar tool  1505  may be configured to impart a controlled force in the direction of arrow  1530  at this time so no damage to the contact assembly results. Solder bumps  1535  may be pre-coated with flux. In some embodiments the coating of flux may not only improve the wetting of the solder to contact protrusions  302   a ,  302   b  it may also enable more efficient heat transfer from contacts  120 ( 1 ) . . .  120 ( 8 ) to the solder bumps. In step  1550 , hot bar tool  1505  may transfer thermal energy through the contacts and into the solder bumps. Once an adequate amount of thermal energy has been transferred into the solder bumps, the solder bumps may transition to a liquid state when heated above their melting temperature. Once in a liquid state, the solder bumps offer little resistance to additional movement of contact assembly  130  in the direction of arrow  1530 . In step  1560 , the contact assembly may then be pushed further by the hot bar tool, causing increased deformation of crushable combs  1225  until hot bar tool  1505  “stops” on flat surface  1320  (see  FIG. 13 ) of ground ring  160 , causing further deformation of crushable combs. In some embodiments crushable combs  1225  may deform between 0.02 mm and 0.12 mm. In other embodiments the crushable combs may deform between 0.05 mm and 0.09 mm. In some embodiments the heating of the crushable combs by hot bar tool  1505  makes them easier to deform. 
       FIG. 14B  depicts the stop position of hot bar tool  1505 . In this figure it can be seen that step  1510  of hot bar tool  1505  may be used to precisely position top surface  401  of contacts  120 ( 1 ) . . .  120 ( 8 ) a known distance below flat surface  1320  (see  FIG. 13 ) of ground ring  160 . In some embodiments, step  1510  has a height between 0.1 and 0.01 mm and thus recesses top surface  401  of contacts  120 ( 1 ) . . .  120 ( 8 ) that same amount below flat surface  1320  of ground ring  160 . In other embodiments, step  1510  is not included and the contacts are pressed flush with flat surface  1320 . Also, during step  1560 , contact protrusions  302   a ,  302   b  on the bottom surface of contact assembly  130  may be wetted by the liquefied solder bumps  1535 . In some embodiments, liquefied solder may enter openings  315   a ,  315   b  (see  FIG. 3A ) in the protrusions, possibly resulting in increased joint strength. In step  1570 , the hot bar tool may then be cooled until the liquefied solder bumps cool to a temperature below the liquidus temperature of the solder alloy and solidify. In step  1580 , the hot bar may then be then retracted and the assembly can be removed from the fixturing. 
     During the descent and final positioning of contact assembly  130  in connector  100 , alignment tabs  1210 , resilient alignment bosses  1215  (see  FIG. 12A ), alignment posts  1220  and crushable combs  1225  may work in conjunction with precision hot bar step  1510  and flat surface  1320  on ground ring  160  to precisely position top surface  401  of contacts  120 ( 1 ) . . .  120 ( 8 ) within connector  100 . More specifically, some embodiments that employ one or more of these features may enable top surface of contacts  401  to be positioned in connector  100  within a tolerance of plus/minus 0.03 mm. In some embodiments top surface of contacts  401  can be positioned within plus/minus 0.025 mm. In further embodiments, top surface of contacts  401  can be positioned within plus/minus 0.02 mm, or less. In some embodiments, as depicted in precise positioning of contact surfaces  401  relative to flat surface  1320  requires the solder bumps  1535  and contact protrusions  302   a ,  302   b  to accommodate manufacturing tolerances.  FIG. 14C  depicts a more detailed view of an embodiment with dual contact assemblies and the interaction of protrusions  302   a ,  302   b  with solder bumps  1535 . More specifically, contact assemblies  130  may be placed in connector  100  relative to flat surfaces  1320 , thus the vertical position of contact protrusions  302   a ,  302   b  relative to PCB  1310  may vary. In some embodiments that variation may be accommodated by the liquefied solder bumps  1535 . Further, some embodiments may have one solder bump for both protrusions while other embodiments may have a separate solder bump for each protrusion. Some embodiments may have one contact receiving pad per contact on PCB  1310  and some embodiments may have more than one contact receiving pad per contact. In some embodiments the contact attachment process may be performed on one side of ground ring  160  at a time, while in other embodiments the process may be performed simultaneously on both sides of the ground ring. 
     In some embodiments, connector  100  may undergo an additional assembly step wherein a partially assembled connector is placed in an insert-molding tool and a thermoplastic or similar dielectric overmold  1605  (see  FIG. 16 ) is formed around contact assembly  130  and within window  1305  of ground ring  160  As depicted in  FIG. 16 , this process may provide a smooth and substantially flat mating surface  1610  in the contact region of ground ring  160 . In some embodiments, dielectric overmold  1605  may be polyoxymethylene (POM). In other embodiments, dielectric overmold  1605  may be a nylon-based polymer. In some embodiments, mating surface  1610  may be disposed below flat surface  1320  of ground ring  160  and be substantially coplanar with the top surface  401  (see  FIG. 4A ) of contacts  120 ( 1 ) . . .  120 ( 8 ). In some embodiments the depression may extend around the entire perimeter of window  1305 . In some embodiments, dielectric overmold  1605  may be used to aid in retaining contacts  120 ( 1 ) . . .  120 ( 8 ) within the connector. More specifically, some embodiments may benefit from ledges  415  (see  FIG. 4A ) on top contact plate  205  or ledges  385  (see  FIG. 3C ) on bottom contact plate  350  to secure contact assemblies  120 ( 1 ) . . .  120 ( 8 ) in dielectric overmold material  1605 . 
     In the foregoing specification, embodiments of the invention have been described with reference to numerous specific details that may vary from implementation to implementation. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The sole and exclusive indicator of the scope of the invention, and what is intended by the applicants to be the scope of the invention, is the literal and equivalent scope of the set of claims that issue from this application, in the specific form in which such claims issue, including any subsequent correction.

Metadata:
Filing Date: 20120907
Publication Date: 20141209
Grant Date: 20141209
Priority Date: 20120907
Inventors: GOLKO ALBERT J.
JOL ERIC S.
LARA-PENA MIGUEL A.
BRZEZINSKI MAKIKO K.
SIAHAAN EDWARD
Assignee: APPLE INC
CPC Classifications: [{"code": "Y10T29/49204", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R43/0263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/405", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R43/0256", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C45/14655", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49204", "inventive": false, "first": false, "tree": "[]"}, {"code": "B29C45/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R12/57", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R43/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R43/0256", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/405", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R43/0263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R12/57", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R43/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "B29C45/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/03", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/405", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01R12/57", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01R43/0256", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R43/0263", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01R13/03", "inventive": true, "first": true, "tree": "[]"}, {"code": "B29C45/14655", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 48170815