Abstract:
A flexible circuit can be cut and spliced to replace a device connected to a removable portion of the circuit. The cut and splice procedure is facilitated by three components, including a service segment integrated into the flexible circuit, a slider assembly that attaches to the flexible circuit within the service segment and a contact assembly that connects to the slider assembly. The service segment is configured with a number of contact pads protected by a detachable insulation layer, which is removed prior to attaching the slider assembly. The flexible circuit can be cut anywhere within a cut zone portion of the service segment in order to detach the removable portion. The slider assembly snaps onto the service segment and provides a convenient straightedge guide within the cut zone. The slider assembly also provides rigid support to the severed end of the remaining flexible circuit, forming a splice plug in conjunction with the contact pads. The contact assembly has a socket that houses contacts corresponding to the contact pads. These contacts are soldered at one end to a replacement flexible circuit. The slider assembly attaches to the contact assembly with the splice plug inserted into the socket to complete the splice. The splice is secured by a locking lever on the contact assembly that retains the slider assembly and a tab on the contact assembly that insures the slider assembly remains attached to the service segment.

Description:
BACKGROUND OF THE INVENTION 
     A flexible or “flex” circuit is a laminate of flexible polyimide film, such as KAPTON®, and a thin sheet of copper etched to produce a pattern of traces and contact pads. An overlying insulation layer is typically used to insulate the copper and environmentally seal the circuit. Flexible circuits include flexible flat cable (FFC) and flexible printed circuits (FPC). The FFC was originally designed as a compact and light-weight interconnect to replace bulky wire harnesses. With the advent of surface-mount electronic components, FPC technology evolved, creating a thin, flexible replacement for conventional rigid printed circuit boards. Flexible circuits provide multiple benefits. A flexible circuit can bend, fold, twist, and be rolled, providing almost unlimited freedom for locating parts and subassemblies. Further, the polyimide film can survive vibration and shock that would damage a rigid board. As a result, design engineers can utilize flexible circuits to solve space, configuration and weight problems that cannot be addressed with conventional wiring or rigid circuit technologies. 
     SUMMARY OF THE INVENTION 
     FIG. 1 schematically depicts a prior art electrical or electronic system  100  utilizing a conventional FFC  102  to interconnect device A  104  and device B  106  to a backplane  108 . A failure of device A  104 , device B  106  or the backplane  108  would require replacement of the entire system  100 . Unlike wiring harnesses, a conventional FFC cannot be cut and spliced in order to replace an interconnected circuit, module or device that has failed. As a result, complete systems must be replaced when any attached component fails, increasing maintenance costs. Alternatively, a connector must be used at each circuit, module or device interface, increasing production costs and reducing reliability. Neither of these alternatives are desirable. 
     The present invention provides an apparatus and method to cut and splice a flexible circuit, combining the servicing advantages of a wiring harness without the associated weight and bulk disadvantages. The flexible circuit service connector according to the present invention provides one or more service segments integrated into a flexible circuit. The service segments can be cut and spliced to remove and replace a flexible circuit portion that is connected to a faulty component, module or device. The service segment functions in conjunction with a slider assembly and contact assembly. The slider assembly attaches to the service segment to create a splice plug from the severed end of the cut flexible circuit. The contact assembly attaches to a replacement circuit and has a socket that mates with the splice plug to complete a splice. 
     One aspect of the flexible circuit service connector is a cut zone portion of the service segment. Advantageously, any cut within the cut zone boundaries, whether straight, crooked or curved, will allow a successful splice. Therefore, it is not critical how the flexible circuit is severed or the tool used to perform the cut. To facilitate detaching a portion of the flexible circuit, however, a portion of the attached slider assembly functions as a straightedge cutting guide situated within the cut zone. An advantageous aspect of the slider assembly is that it requires no special installation tools to attach it to the service segment. The slider assembly simply snaps onto a notched portion of the service segment. The slider assembly is also removable and reusable. An advantageous aspect of the contact assembly is that it removably locks to the slider assembly, increasing splice reliability yet allowing the splice to be disconnected. Further, retaining tabs on the contact assembly secure together the snap-on portions of the slider assembly when the slider assembly is locked to the contact assembly, also insuring a reliable splice. 
     Another aspect of the present invention is a service connector utilizing a flexible circuit having a thin layer of conductive material. The service connector includes a service segment portion of the flexible circuit. Within the service segment, the flexible circuit conductive material is patterned as a plurality of contact pads. The service segment divides the flexible circuit into a removable portion and a remaining portion. The flexible circuit can be severed within the service segment in order to detach the removable portion. This creates a severed end terminating the remaining portion of the flexible circuit. At least a portion of each of the contact pads is located on the remaining portion near the severed end. A slider attaches to the service segment to support the remaining portion severed end and the associated contact pads. An insulator provides a socket that is configured for insertion of the slider. A plurality of contacts are installed within the socket. Each of the contacts connect to a replacement circuit and, when the slider is inserted into the socket, also to a corresponding one of the contact pads. 
     Yet another aspect of the present invention is a method of cutting off a removable portion of a flexible circuit and splicing a replacement circuit to a remaining portion of the flexible circuit. This cut and splice method comprises the step of providing a service segment between the removable portion and the remaining portion of the flexible circuit, with the remaining portion having a plurality of contact pads. Another step is attaching a support to the remaining portion within the service segment. Yet another step is severing the flexible circuit within the service segment so as to detach the removable portion from the remaining portion. Further steps are installing a plurality of contacts within an insulator and electrically connecting the plurality of contacts to the replacement circuit. One other step is mating the support to the insulator so as to provide electrical communication between each of the contacts and a corresponding one of the contact pads. 
     A further aspect of the present invention is a service connector for severing a flexible circuit to detach a removable portion of the flexible circuit from a remaining portion of the flexible circuit and for creating a splice between a replacement circuit and a severed end of the remaining portion. The service connector has a service segment means for providing a plurality of contact pads on the remaining portion. The assembly also has a splice plug means for supporting the severed end and the contact pads, where the splice plug means is attachable to the service segment means. Further elements of the service connector are a socket means for engaging the splice plug means and a contact means installed within the socket means for providing electrical connection to the contact pads when the splice plug means engages the socket means. The contact means is connectable to the replacement circuit so as to provide electrical communications between the replacement circuit and the remaining portion when the splice plug engages the socket means, thereby completing the splice. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic of a prior art flexible flat cable (FFC) interconnecting multiple devices; 
     FIG. 2 is a schematic of a FFC interconnect incorporating a flexible circuit service connector according to the present invention; 
     FIG. 3 is an expanded top view of a service segment; 
     FIG. 4 is a perspective view of a protective layer for the service segment contact pads; 
     FIG. 5 is a perspective, exploded view of a service segment and attached slider assembly; 
     FIG. 6 is a perspective top view of a service segment and attached slider assembly; 
     FIG. 7 is a bottom view of a service segment, a cut zone and an attached slider assembly; 
     FIG. 8 is a perspective view of an unconnected slider assembly and contact assembly; 
     FIG. 9 is a perspective view of an unconnected splice socket and mating splice plug; 
     FIG. 10 is a perspective top view of a completed splice; 
     FIG. 11 is a perspective bottom view of a completed splice; 
     FIG. 12 is a perspective view of contacts installed in an associated insulator and connected to a replacement flexible circuit; 
     FIG. 13 is a bottom perspective view of the insulator housing illustrating installation of the strain relief; 
     FIG. 14 is a top view of the service segment; 
     FIGS. 15A-F are top, perspective, back, side and sectional views of the slider; 
     FIGS. 16A-E are top, perspective, front, side and bottom views of the lock; 
     FIGS. 17A-G are top, perspective, front and side, sectional and detailed views of the insulator; 
     FIGS. 18A-C are top, detail and sectional views of a contact; 
     FIGS. 19A-D are top, perspective, front and side views of a strain relief bottom; and 
     FIGS. 20A-D are top, perspective, front and side views of a strain relief top. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Overview 
     FIG. 2 illustrates one embodiment of a flexible circuit service connector having a service segment  300 , a slider assembly  500  and a contact assembly  800  according to the present invention. Unlike a conventional system  100  (FIG.  1 ), the electrical or electronic system  200  utilizes an FFC interconnect  210  having a service segment  300  incorporated near each device  104 ,  106 . Advantageously, this allows a failed device to be cut  212  from the system  200  and a replacement device  206  to be spliced into the system  200  without replacing the FFC interconnect  210  and all of the attached devices. 
     As an example, FIG. 2 assumes a failure of device B  106 . The slider assembly  500  is attached to the service segment  300  nearest the failed device  106 . The FFC  210  is cut  212  within that particular service segment  300  to detach a removable FFC portion  270  from a remaining FFC portion  280 , allowing device B  106  to be removed. The contact assembly  800  is attached to a replacement FFC  290 , which connects to a replacement device  206 . Contact pads  340  at the severed end of the remaining FFC portion  280  and the attached slider assembly  500  are plugged into the contact assembly  800 , forming a splice between the remaining FFC portion  280  and the replacement FFC  290 . This electrically connects the replacement device  206  to the system  200 , completing its repair. 
     The described flexible circuit service connector thus achieves the cut and splice convenience of a wire harness assembly and the compactness, flexibility and weight advantages of FFC. Although described above with respect to a FFC, the flexible circuit service connector is also applicable to the removal, repair or replacement of portions of a flexible printed circuit (FPC) having surface-mounted or through-hole components, a semi-rigid circuit, a circuit with FFCs or FPCs combined with rigid circuit boards, or any similar technology, referred herein generally as “flexible circuits.” 
     The Service Segment 
     FIG. 3 illustrates a service segment  300  incorporated into a flexible circuit  310 . The service segment  300  is an area of predetermined length and width that divides the flexible circuit  310  into a removable portion  312  and a remaining portion  314 . The service segment  300  has contact pads  340 , keyed notches  320 ,  330 , and a cut zone  360 . The contact pads  340  are portions of the flexible circuit  310  conductive material patterned as a multiplicity of parallel, evenly-spaced generally rectangular regions separated by the flexible circuit  310  insulator material. The contact pads are generally in electrical continuity with various traces patterned from conductive material throughout the flexible circuit. The keyed notches are cutouts in the edges of the flexible circuit  310  and include a wide notch  320  and a narrow notch  330 , which orient the slider  502  (FIG. 5) attachment to the service segment  300 , as described below with respect to FIGS. 5-6. The cut zone  360  is an area within the service segment  300  defining the boundaries where the flexible circuit  310  can be severed in order to separate the removable portion  312  from the remaining portion  314 . The dimensions of the cut zone  360  and its location within the service segment  300  are determined by characteristics of the slider assembly  500  (FIG. 5) and the contact assembly  800  (FIG.  8 ), as described below with respect to FIG.  7 . The service segment  300  is described in detail with respect to FIG.  14 . 
     The Slider Assembly and the Flexible Circuit Cut Procedure 
     FIGS. 4-7 describe the slider assembly  500  and the cut aspect of the flexible circuit cut and splice procedure. The slider assembly  500  is described in detail with respect to FIGS. 15-16. 
     FIG. 4 illustrates a protective cover  400  that covers the service segment  300  until it is used. The protective cover  400  is an adhesive-backed insulator, such as mylar tape, that is removed from a service segment  300  before attaching a slider assembly  500  (FIG. 5) and before performing a cut and splice. The cover  400  insulates the contact pads  340  to prevent inadvertent electrical shorts and to environmentally protect the pads  340  to retard oxidation and corrosion. 
     As shown in FIG. 5, the slider assembly  500  snaps onto a service segment  300 . The slider assembly  500  has a slider  502  and a lock  504 . The slider  502  is oriented beneath the flexible circuit underside  308  so that the wide key  520  aligns with the wide notch  320  and the narrow key  530  aligns with the narrow notch  330 . The slider keys  520 ,  530  and the keyed notches  320 ,  330  insure that the slider  502  is aligned with the planar shelf  510  extending toward the contact pads  340 . The slider  502  is then positioned within the notches  320 ,  330  so that the flexible circuit underside  308  contacts the shelf top face  512 , with the shelf  510  supporting the contact pads  340 . 
     Also shown in FIG. 5, the lock  504  is oriented above the flexible circuit topside  306  with the locking tabs  590  extending toward the slider sockets  540 . The lock bottom face  580  has a wide indent  584  (FIG. 16E) and a narrow indent  586  (FIG. 16E) that match with that the wide key  520  and narrow key  530 , respectively. The keyed indents  584 ,  586  insure the lock  504  is aligned with the cutout  570  facing the contact pads  340 . The lock  504  snaps onto the slider  502  by inserting the tabs  590  into the sockets  540 . A locking tab latch  594  (FIG. 16C) engages with a socket catch  542  (FIG. 15F) securing together the lock  504 , the flexible circuit  310  and the slider  502 , as shown in FIG.  6  and described below. 
     FIGS. 6-7 illustrate the slider assembly  500  attached to a service segment  300 . As shown in FIG. 6, the attached slider assembly  500  is configured so that the flexible circuit  310  is retained between the lock bottom face  580  and the shelf top face  512  (FIG. 5) and so that the slider  502  is retained within the service segment notches  320 ,  330  (FIG.  5 ). The slider shelf  510  extends underneath and supports the contact pads  340 . The slider assembly  500  can be disengaged from the flexible circuit  310  by unsnapping the slider  502  and lock  504  portions. This is accomplished by simultaneously pressing the lock releases  592 . This disengages the locking tabs  594  (FIG. 16C) from the socket catches  542  (FIG.  15 F), allowing the lock  504  to be lifted from slider  502  and the slider assembly  500  to be removed from the flexible circuit  310  and reused. 
     FIG. 7 illustrates the flexible circuit underside  306  with the attached slider assembly  500 . Within the service segment  300  is a cut zone  362  (shaded area). The flexible circuit  310  can be severed across any portion of the cut zone  362 . Advantageously, the cut does not have to be precisely straight, because registration of the contact pads  340  (FIG. 3) and the contacts  900  (FIG. 9) is not dependent on location of the severed end within the contact assembly socket  830  (FIG.  9 ). Thus, a successful splice can be achieved when the flexible circuit  310  is cut with many different tools along a straight, curved or even jagged line, so long as the cut is entirely within the cut zone  362 . 
     Also shown in FIG. 7, a cutting guide is provided by the slider straightedge  514 , which lies within the cut zone  362 . In a particular embodiment, the cut zone extends a distance  364  of 5 mm in front of the straightedge  514  and a distance  366  of 5 mm in back of the straightedge  514 , for a total length of 10 mm. The front distance  364  is limited by the space between the straightedge  514  and the insulator housing inside wall  820  (FIG. 17F) when the slider assembly  500  and the contact assembly  800  are fully engaged. The back distance  366  is limited by the distance from the insulator housing inside wall  820  (FIG. 17F) to an installed contact tip  934  (FIG.  17 B). 
     The Contact Assembly and the Flexible Circuit Splice Procedure 
     FIGS. 8-11 illustrate the contact assembly  800  and its use for splicing a replacement flexible circuit  808  to the remaining flexible circuit  314  after the cut procedure described above. FIGS. 8-9 illustrate the splice plug  700  and mating contact socket  830  prior to completing the splice operation. In particular, FIG. 8 focuses on the splice plug  700  formed from the service segment contact pads  340  and attached slider assembly  500  after cutting away the removable portion  312  (FIG. 7) of the flexible circuit  310  (FIG.  7 ). FIG. 9 focuses on the mating contact socket  830  portion of the contact assembly  800 . The contact assembly  800  is described in detail with respect to FIGS. 17-20. 
     As shown in FIG. 8, the contact assembly  800  has an insulator  802  and a strain relief  804 ,  806  and is connected to a replacement flexible circuit  808 . As described below with respect to FIGS. 12-13, the contact assembly  800  is pre-attached to the replacement flexible circuit  808 . The replacement flexible circuit  808 , may, in turn, be connected to a replacement device (not shown). To splice the remaining flexible circuit  314  to the replacement flexible circuit  808 , the slider assembly  500  is positioned opposite the contact assembly  800 . The splice is achieved by utilizing the release guards  548  to grip the slider assembly  500  and, simultaneously gripping the contact assembly  800 , pressing the two assemblies together (see FIG.  10 ). In making the splice, the splice plug  700  is inserted into the contact socket  830 . Each of the contact pads  340  connect with a corresponding contact  900  (FIG. 9) housed within the socket  830 , establishing an electrical connection between the remaining flexible circuit  314  and the replacement flexible circuit  808 . The insulator tab  822  fits within the lock cutout  570 , securing the lock  504  and the slider  502  together and preventing them from disengaging once the splice has been achieved. 
     As shown in FIG. 9, the insulator  802  has a splice socket  830  configured to accept the splice plug  700 . The socket  830  houses a multiplicity of contacts  900  that are fitted into slots  836  (FIG.  17 E). The insulator  802  has guides  848  that help position the plug  700  into the socket  830 . The guides  848  in conjunction with the tab  822  serve to maintain the attachment together of the slider  502  and lock  504 . A locking lever  840  latches the contact assembly  800  to the slider assembly  500 , as described below with respect to FIG.  11 . The slider assembly  500  mates with the contact assembly  800  in a manner that the contact pads  340  make an electrical connection with contacts  900  located within the insulator  802 . The contact pads  340  are in electrical continuity with trace conductors within the remaining flexible circuit  314 . The contacts  900  are soldered to solder pads  809  (FIG. 12) that are in electrical continuity with trace conductors within the replacement flexible circuit  808 . Thus, the attachment of the slider assembly  500  and the contact assembly  800  splices the conductors within the remaining flexible circuit portion  314  to the conductors in the replacement flexible circuit  808 . 
     Also shown in FIG. 9, each of the contacts  900  correspond to one of the contact pads  340  of the splice plug  700 . Registration of the contacts  900  with the contact pads  340  is achieved with the location of the slider keys  520 ,  530  (FIG. 5) within the service segment notches  320 ,  330  (FIG. 5) and the location of the shelf sides  516  against the inside of the socket side walls  832 . Specifically the notches  320 ,  330  locate the contact pads  340  with respect to the slider shelf  510 , and the shelf sides  516  locate the shelf  510  with respect to the socket  830 , thereby locating the contacts  900  with respect to the contact pads  340 . 
     FIGS. 10-11 illustrate the completed splice of the remaining flexible circuit portion  314  to the replacement flexible circuit  808 . The slider assembly  500  is attached to the contact assembly  800 . The contact assembly locking lever  840  is inserted through the slider assembly locking slot  550 . In doing so, a lever catch  842  slides along a beveled portion  558  (FIG. 15E) of the slot  550 . This lifts the lever  840  over the slot  550  until the catch engages the back wall  552  of the slot  550 , retaining the lever  840  within the slot  550  and the slider assembly  500  attached to the contact assembly  800 . In this position the slider assembly  500  is engaged on one side by the insulator tab  822  fitted within the lock cutout  570  and on the other side by the guides  848  pressed against the raised stop portion  519  of the shelf bottom face  517  (FIG.  15 D). Thus, the tab  822  and guides  848  serve to secure the attachment of the lock  504  to the slider  502 , advantageously preventing wear or inadvertent pressure on the releases  592  from allowing the flexible circuit  314  to disengage from the slider assembly  500 . 
     Contact Assembly Attachment to the Replacement Circuit 
     FIGS. 12-13 illustrate the attachment of the contact assembly  800  to a replacement flexible circuit  808 . FIG. 12 illustrates connection of contacts  900  to the replacement flexible circuit  808 . The contacts  900  are described in detail below with respect to FIGS. 18A-C. The contacts  900  are pressed into slots  836  that extend from the insulator back plate  818  into the insulator socket  830  (not visible). Each contact  900  has a soldertail  970  that extends from the back plate  818 . The soldertails  970  of the installed contacts  900  are soldered to the corresponding solder pads  809  on the end of the replacement flexible circuit  808 . In this manner, the insulator  802  and the corresponding installed contacts  900  are physically attached to the replacement flexible circuit  808 . Further, the contacts  900  are electrically connected to conductors within the replacement flexible circuit  808  via the solder pads  809 . The insulator  802  is also physically connected to the flexible circuit  808  by heat stakes  826  (FIG. 13) as described below. 
     FIG. 13 illustrates installation of the strain relief bottom  804  and top  806  onto the insulator  802  and replacement flexible circuit  808 . The insulator heat stakes  826  are mounted through corresponding flexible circuit holes  807 . Corresponding holes  868  on the strain relief bottom  804  are mounted over the heat stakes  826  so that the flexible circuit  808  is between the strain relief top face  861  and the insulator bottom face  814 . The heat stakes  826  are then melted, securing together the flex circuit  808 , the strain relief bottom  804  and the insulator  802 . The strain relief top  806  slides onto the insulator  802  with the tongues  824  fitted within the grooves  886 . The strain relief top  806  snaps onto the strain relief bottom  804  with the tabs  898  inserted into the bottom sockets  874 . The latches  899  at the tip of the tabs  898  engage the catches  875  inside the sockets  874 , attaching together the strain relief bottom  804  and top  806  with the flexible circuit  808  secured between the top clamp  896  and the top face  861 . Accordingly, any strain on flex circuit  808  is distributed to the clamp  896 , top face  861  and insulator heat stakes  826  rather than solely to solder joints between contact soldertails  970  and flex circuit solder pads  809 . Further, the strain relief top  806  covers the exposed portions of the contacts  900  and solder pads  809 , providing some environmental protection and insulation from inadvertent shorts. Although the contact assembly  800  is described above as attached to a replacement flexible circuit  808 , one of ordinary skill will recognize that a contact assembly can be configured for like or similar attachment to a rigid circuit board or for equivalent incorporation into any circuit, module or device. 
     Service Segment Details 
     FIG. 14 illustrates details of a particular service segment  300  embodiment. The service segment  300  has 38 contact pads  340  each 1×14 mm on 1.5 mm centers. The service segment  300  is 29 mm ( 393 )×62.3 mm ( 392 ) and is depicted on a 72 mm wide ( 391 ) flexible circuit  310 . The wide notch  320  is 6 mm×2.15 mm. The narrow notch  330  is 3.5×2.15 mm. The wide notch  320  is located 1 mm ( 394 ) from the boundary of the service segment  300 . The narrow notch  330  is located 2.25 mm ( 395 ) from the boundary of the service segment  300 . Each edge of the service segment  300  has a 2° ( 396 ) bevel, so that the service segment  300  is wider nearer the notches  320 ,  330 . This bevel facilitates insertion of the remaining portion  314  severed end into the insulator socket  830  (FIG. 9) to complete a splice. 
     One of ordinary skill will recognize that a service segment  300  is not limited to 38 contact pads  340 . Embodiments having between 5 and 50 contact pads  340  may be of particular utility, although it is contemplated that a service segment with fewer than 5 or greater than 50 contact pads  340  is within the scope of the present invention. It should also be recognized that some of the contact pads  340  may not be used, i.e. connected to other traces within the flexible circuit  310 . Further, the embodiment of a service segment  300  depicted in FIG. 14 has a width  392  that is less than the width  391  of the flexible circuit  310 . One of ordinary skill will recognize that the service segment can be equal to or greater than the width of the surrounding flexible circuit  310 . 
     Slider Assembly Details 
     FIGS. 15-16 illustrate details of slider assembly  500  (FIG. 6) components. FIGS. 15A-F illustrate detailed features of the slider  502 . As described above with respect to FIGS. 5-7, the slider  502  forms the bottom half of the slider assembly  500  (FIG. 6) and is attached to a service segment  300  (FIG. 3) with a snap-on lock  504  (FIG.  5 ). Also described above with respect to FIGS. 8-9, the slider  502 , in conjunction with contact pads  340  (FIG. 8) on the severed end of a remaining flexible circuit portion  314  (FIG. 8) forms a splice plug  700  (FIG. 8) to splice into a contact assembly socket  830  (FIG.  9 ). 
     As shown in FIGS. 15A-F, the slider  502  has a planar shelf  510 , a wide key  520 , a narrow key  530 , sockets  540 , guards  548  and a locking slot  550 . The shelf  510  has a top face  512  and an opposite bottom face  517 . Forming the periphery of the shelf  510  between the top face  512  and bottom face  517  is a straightedge  514 , sides  516 , and a back edge  518 . The top face  512  has a chamfer  513  extending between the sides  516  along the straightedge  514 . The contact tip leading edge  932  (FIG. 18B) compresses the flexible circuit  314  (FIG. 8) and contact pads  340  (FIG. 8) against the chamfer  513  upon insertion of the splice plug  700  (FIG. 8) into the contact socket  830  (FIG.  8 ). In this manner, the contact point  934  (FIG. 18B) slides along the contact pads  340  (FIG. 8) with increasing pressure as the contact tip  930  (FIG. 18B) travels up the slope of the chamfer  513  to the thickest part of the shelf  510 . At full insertion of the splice plug  700  (FIG. 8) into the contact socket  830  (FIG.  8 ), the contact pads  340  (FIG. 8) conform to the trailing edge  936 , point  934  and leading edge  932  of the contact tip  930  (FIG.  18 B), creating a gas-tight connection. 
     Also shown in FIGS. 15A-F, the top face  512  has a wide key  520  and a narrow key  530  each positioned near one of the sides  516 . The bottom face  517  has a raised stop portion  519  that extends between the sides  516  along the back edge  518 . The sockets  540  extend from each side  516  adjacent the back edge  518  and perpendicular to the shelf  512  from the raised stop portion  519  to beyond the top face  512 . Each socket  540  has catches  542 , release slots  544  and release guards  548 . The catches  542  are located on opposite interior sides of each socket  540  adjacent the release slots  544 . Each socket  540  defines or forms an external slot  544  that accepts the lock release  592  (FIG.  16 C). A raised bar  552  and a generally rectangular cutout portion  554  of the back edge  518  define a locking slot  550 . The bar  552  has a beveled portion  558  sloping down toward the straightedge  514 . 
     In a particular embodiment, the slider  502  is 23×81.5 mm overall. The shelf  510  is 23×62.65×3.8 mm. The chamfer  513  is 10° and 6.448 mm in length. The sockets  540  are 7.5×7.425×8.4 mm. The back edge  518  is 62.65×5.65 mm. The wide key  520  and narrow key  530  are 6.1×2.15×2 mm and 3.25×2.15×2 mm, respectively. The socket  540  plus guard  548  are 9 mm in length. The slider  502 , lock  504  (FIG.  16 B), insulator  802  (FIG.  17 B), strain relief bottom  804  (FIG. 19B) and strain relief top  806  (FIG. 20B) are each injection molded as one piece using a polybutylene terephthalate (PBT) resin with added fiberglass, fire retardant and flow enhancer. One such resin is VALOX  553 , which is 30% glass reinforced and available from GE Plastics, One Plastics Avenue, Pittsfield, Mass. 01201. 
     FIGS. 16A-E illustrate detailed features of the lock  504 . As described above with respect to FIGS. 5-7, the lock  504  forms the top half of the slider assembly  500  (FIG. 6) and snaps onto the slider  502  (FIG. 5) securing the slider  502  (FIG. 5) with respect to the service segment  300  (FIG.  3 ). The lock  504  has a top face  560 , a cutout  570 , a bottom face  580 , and locking tabs  590 . The top face  560  is generally rectangular, having a front edge  562 , back edge  564  and ends  566  around its periphery. The top face  560  defines a cutout  570  extending from the interior of the top face  560  to the front edge  562  and along the front edge  562  toward both ends  566 . The bottom face  580  is opposite the top face  560 . The tabs  590  extend generally perpendicularly away from the bottom face  580  proximate each end  566 . Blocks  596  extend generally perpendicularly away from the bottom face  580  proximate each tab  590  and function as positioning and strengthening structures. Each tab  590  has a release  592  extending past the ends  566  and generally perpendicularly to the tab  590 . The end of each tab  590  has a latch  594 . The bottom face  580  also has a raised portion  582  between the tabs  590 . The raised portion  582  forms a wide indent  584  and a narrow indent  586 . 
     In a particular embodiment, the lock top face  560  is 8×77.5 mm. The lock  504  is 4.8 mm thick at the back edge  564  and 2.2 mm thick at the ends  566 . The cutout  570  is 4 mm in length and 24.25 mm wide at the front edge  562 , forming a 45° angle along the top face  560 . The tabs  590  are 10.3 mm in depth from the top face  560 . The indents  584 ,  586  are 2.1 mm in depth from the raised portion  582 . The distance between the tabs  590  is 69.9 mm. The widest width of the raised bottom face portion  582  is 62 mm, and the narrowest width is 57.5 mm. The releases  592  extend 2.5 rmm from each end  566 . 
     Contact Assembly Details 
     FIGS. 17-20 illustrate details of contact assembly  800  (FIG. 8) components. FIGS. 17A-G illustrate detailed features of the insulator  802 . As described above with respect to FIGS. 8-9, the insulator  802  houses contacts  900  that form the splice between the severed end of the remaining flexible circuit  314  and the replacement flexible circuit  808 . To do this, the contact assembly  800  mates with and locks to the slider assembly  500 . 
     As shown in FIGS. 17A-F, the insulator  802  has a housing  810 , a tab  822 , a socket  830  and a locking lever  840 . The housing  810  has a top wall  812 , an opposite bottom wall  814 , side walls  816  and a slotted back wall  818  that form or define the socket  830  between the tab  822  and the locking lever  840 . The tab  822  extends from a front portion of the top wall  812 . The locking lever  840  and two guides  848  extend from a front portion of the bottom wall  814 . The locking lever  840  has a latch  842  protruding away from the bottom wall  814  and along the width of the lever  840 . Extending from the bottom wall  814  are three heat stakes  826 . Strain relief tongues  824  extend from each side wall  816  along the back wall  818 . Slotted liners  834  extend across the interior portion of the top wall  812  and bottom wall  814 . The slotted back wall  818  and slotted liners  834  form or define slots  836  that extend from the back wall  818  into the top and bottom portions of the socket  830 . Each slot  836  has stops  838  along the back wall  818 . 
     In a particular embodiment, the insulator housing  810  is generally 23×71.3×12 mm, including the tongues  824  along the back wall  818 . The tongues  824  are 3.3 mm thick. The bottom wall  814  is 1.925 mm thick. The guides  848  extend 8 mm from the socket  830 . The socket  830  is 17×62.8×8.15 mm. The locking lever  840  is 1.5 mm thick and 16 mm wide and extends 34.086 mm from the back wall  818 . The latch  842  on the locking lever  840  is located 29 mm from the back wall  818  and is angled at 35°. The tab  822  is 6.85×23.5 mm and has a 45° bevel. The heat stakes  826  are 2.5 mm in diameter and 3 mm in length. 
     FIGS. 18A-C illustrate detailed features of a contact  900 . As described above with respect to FIGS. 8,  9  and  12 , a multiplicity of contacts  900  form the electrical connection between the remaining flexible circuit  314  (FIG. 8) and the replacement flexible circuit  808  (FIG. 8) to complete a splice. Each contact  900  has a top edge  901 , bottom edge  902 , base  910 , arm  920 , tip  930 , support  940 , cavity  950 , back edge  960  and soldertail  970 . The base  910  has stops  912 , barbs  914  and a front edge  916 . The stops  912  extend from both the top edge  901  and bottom edge  902  along the back edge  960 . Barbs  914  are positioned on the top edge  901  proximate the stop  912 . The arm  920  extends from the front edge  916  and ends at the tip  930 . The support  940  extends from the front edge  916  opposite the arm  920 . The arrn  920 , support  940  and front edge  916  form or define a U-shaped cavity  950 . An indent  962  forms a detach point for a multiple contact carrier (not shown). The soldertail  970  extends from the back edge  960  proximate the bottom edge  902 . The tip  930  has a leading edge  932 , contact point  934  and trailing edge  936 . 
     In a particular embodiment, the contacts  900  are made of WRM Alloy  4085  available from Waterbury Rolling Mills, Inc., 240 E. Aurora Street, Waterbury, Conn. 06708. The contacts  900  are stamped from 0.510 mm thick material with an attached 3.8 mm carrier having a 11 mm progression. The contacts  900  are machine pressed into the insulator slots  836  (FIG. 12) from the back wall  818  (FIG.  12 ). The support  940  is 19.3 mm in length from the back edge  960  and 1.45 mm in depth. The arm  920  is 15.8 mm from the stop  912  at the top edge  901  to the contact point  934 , with a beam of 1 mm. The arm  920  deviates 2° toward the support  940 . The base  910  is 9.95 mm between the top edge  901  and bottom edge  902  at the stops  912  and 8.05 mm at a point between the barbs  914 . The indent  962  is 0.5×3 mm. Between the contact point  934  and support  940  is 3.751 mm. Between the end of the soldertail  970  and the contact point  934  is 23.489 mm. The tip leading edge  932  is at 35°. 
     FIGS. 19A-D illustrate detailed features of the strain relief bottom  804 . As described above with respect to FIGS. 12-13, the strain relief bottom  804  is heat staked to the insulator  802  (FIG. 13) and replacement flexible circuit  808  (FIG. 13) and snaps together with the strain relief top  806  (FIG. 13) as a strain relief to the solder joints connecting the contact soldertails  970  (FIG. 12) to the flexible circuit solder pads  809  (FIG.  12 ). The bottom  804  is a generally rectangular, planar piece having a top face  861 , bottom face  862 , side edges  865 , front edge  866 , back edge  867  and heat stake holes  868 . The bottom face  862  is generally flat. The top face  861  has raised portions  870  extending from the back edge  867  and along each side edge  865 . The raised portions  870  define indents  872  proximate the front edge  866  and sockets  874  proximate the back edge  867 . Posts  877  extend perpendicularly to the top face  861  from each side edge  865 . In the interior of each socket  874  is a catch  875 . 
     In a particular embodiment, the strain relief bottom  804  is generally 23.2×74.5×1.5 mm. Along the front edge  866  to the posts  877 , the width is 68 mm. The raised portions  870  are 3 mm thick. The posts  877  are 5 mm in height and 16.2 mm from the back edge  867 . The heat stake holes  868  are 2.9 mm in diameter and spaced 27.5 mm apart and 5 mm from the front edge  866 . The sockets  874  are 5×2.5×3 mm. The catches  875  extend 0.75 mm from the inside walls of the sockets  874  at a 35° angle. 
     FIGS. 20A-D illustrate detailed features of the strain relief top  806 . As described above with respect to FIGS. 12-13, the strain relief top  806  slides onto the insulator tongues  824  (FIG. 13) and snaps onto the strain relief bottom  804  (FIG. 13) to provide strain relief to the solder joints connecting the contact soldertails  970  (FIG. 12) to the flexible circuit solder pads  809  (FIG.  12 ). The top  806  also covers, insulates and protects the contacts  900  (FIG. 12) and solder pads  809  (FIG.  12 ). The top  806  has a front plate  880  and a bottom plate  890  that are generally perpendicular to each other. An angular section  892  joins the front plate  880  and bottom plate  890 . The front plate  880  has a front face  888 . The bottom plate  890  has a bottom face  894  and a clamp  896  that is a raised portion of the bottom face  894 . Side walls  882  extend generally perpendicularly from the ends of the front plate  880 . Corners  884  extend generally perpendicularly and inwardly from each side wall  882 . The front face  888 , side walls  882  and corners  884  form or define grooves  886 . Tabs  898 , each with a latch end  899 , extend generally perpendicularly and downwardly from the bottom face  894 . 
     In a particular embodiment, the strain relief top  806  is generally 16×74.5×10.7 mm, excluding the tabs  898  and the clamp  896 . The angular section  892  is at 450° to the front  880  and bottom  890  plates. The tabs  898  extend 3 mm from the bottom face  894 , are 4.25 mm across and each have a 45° catch. There is 67.65 mm between the tabs  898 . The bottom plate  890  is 3.05 mm thick along the clamp portion  896 . The clamp  896  is 2.65 mm×62.3 mm and beveled 45° proximate the front plate  880 . The front plate  880  is 2.2 mm thick. The side walls  882  extend 8 mm from the back of the front plate  880 . There is 68.3 mm between the ends of the corners  884 , which are 2.35 mm across. 
     The flexible circuit service connector has been disclosed in connection with various embodiments of the present invention and in connection with cutting a faulty device from a flexible circuit and splicing a replacement device to the flexible circuit. Other applications of the present invention include, for example, upgrading portions of a flexible circuit assembly, bypassing portions of a flexible circuit assembly, and cutting and splicing a FFC to a desired length. One of ordinary skill in the art will appreciate many variations and modifications of the disclosed embodiments and various applications within the scope of this invention.