Abstract:
Disclosed herein is an implantable electronic device. The device has a housing and a header connector assembly coupled to the housing. The header connector assembly has a connector assembly and a header enclosing the connector assembly. The connector assembly has a subassembly including an electrically conductive component at least partially residing within a first material that is provided about the electrically conductive component. The header has a second material that is provided about the connector assembly and the subassembly subsequent to the first material setting up about the electrically conductive component.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application Ser. No. 62/209,767, filed Aug. 25, 2015, titled “Method for Creating a Fused Thermoplastic-Conductor Subassembly for use In Manufacturing an IPG Header,” and is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    Aspects of the present invention relate to medical apparatus and methods. More specifically, the present invention relates to systems and methods for manufacturing a header connector assembly of an implantable electronic device such as an implantable pulse generator or implantable cardiac monitor. 
       BACKGROUND OF THE INVENTION 
       [0003]    Implantable electronic devices (IEDs) include pulse generators (IPGs) such as pacemakers and implantable cardioverter defibrillators (ICDs), which are used in the treatment of cardiac conditions, and neuromodulators or neurostimulators, which are used in chronic pain management or the actuation and control of other body systems. These IPGs commonly include a housing, feedthrus, and a connector assembly that is enclosed in a header. Electrical stimulation originating in the housing is led to the connector assembly through feedthrus. The connector assembly serves to transmit electrical signals out of the IPG and to a lead electrically connected to the connector assembly, the lead transmitting electrical signals between the IPG and patient tissue. 
         [0004]    Other IEDs include implantable cardiac monitors (ICMs), which also employ a housing and a header. ICMs are used to monitor heart function or other electrical signals, but do not administer electrotherapy. 
         [0005]    A header of an IED encloses the connector assembly, which has many internal electrically conductive components such as, for example, wires, ribbon, antennas, blocks, rings, etc. In order for the IED to have proper functionality when implanted, certain spacing between the electrically conductive components of the connector assembly should be maintained during installation into the header, regardless of whether the header and connector assembly are joined together via a cast-in-place process, an injection molding process or any other type of process. Accordingly, there is a need in the art for an IED with more reliably spaced connector assembly components and a method of manufacturing offering improved reliability with respect to component spacing. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    Disclosed herein is an implantable electronic device. In one embodiment, the device includes a housing and a header connector assembly coupled to the housing. The header connector assembly includes a connector assembly and a header enclosing the connector assembly. The connector assembly includes a subassembly including an electrically conductive component at least partially residing within a first material that was provided about the electrically conductive component. The header includes a second material that was provided about the connector assembly and the subassembly subsequent to the first material setting up about the electrically conductive component. 
         [0007]    In one embodiment, the first material includes a thermoplastic. The thermoplastic may have been provided via melting. The melting may have been brought about via at least one of inductive heating, Ohmic heating or laser heating of the electrically conductive component. The thermoplastic may include at least one of TECOTHANE, PELLETHANE, BIONATE or ELASTHANE. The subassembly may be a fused thermoplastic-conductor subassembly. The second material may include epoxy, silicone rubber, polyurethane, TECOTHANE, PELLETHANE, BIONATE, or ELASTHANE. The second material may be provided via at least one of a backfilling process, an overmolding process, an injection molding process, or a casting process. The electrically conductive component includes at least one of a wire, ribbon, antenna, block, or ring. 
         [0008]    Depending on the embodiment, the implantable electronic device may include an implantable pulse generator for administering electrotherapy via an implantable medical lead configured to couple with the implantable pulse generator. Alternatively, the implantable electronic device may include an implantable cardiac monitor. 
         [0009]    Also disclosed herein is a method of manufacturing an implantable electronic device. In one embodiment, the method includes: forming a fused thermoplastic-conductor subassembly by causing an electrically conductive component of a connector assembly of a header connector assembly to fuse to a thermoplastic; and forming a header of the header connector assembly about the fused thermoplastic-conductor subassembly. 
         [0010]    In one embodiment, the fusing is brought about by melting the thermoplastic via at least one of Inductive heating, Ohmic heating or laser heating of the electrically conductive component. The thermoplastic may include at least one of TECOTHANE, PELLETHANE, BIONATE, or ELASTHANE. The electrically conductive component may include at least one of a wire, ribbon, antenna, block, or ring. The header may be formed about the thermoplastic-conductor subassembly via at least one of a backfilling process, an overmolding process, an injection molding process, or a casting process. 
         [0011]    In one embodiment, the thermoplastic includes at least two opposed portions and the electrically conductive component is sandwiched between the two opposed portions prior to the electrically conductive component being fused to the thermoplastic. The sandwiched opposed portions and electrically conductive component may be compressed between pressure platens when the electrically conductive component is being fused to the thermoplastic. 
         [0012]    In one embodiment, the thermoplastic is placed on a single side of the electrically conductive component, which is maintained in close intimate contact with the thermoplastic when the electrically conductive component is being fused to the thermoplastic. 
         [0013]    The method of manufacturing may be employed in the manufacture of an implantable electronic device including an implantable pulse generator for administering electrotherapy via an implantable medical lead configured to couple with the implantable pulse generator. The method of manufacturing may also be employed in the manufacture of an implantable electronic device comprises an implantable cardiac monitor. 
         [0014]    In one embodiment of a method of fabricating a thermoplastic-conductor subassembly for IPG headers, the method includes molding one thermoplastic component or two mating thermoplastic components. The one or more thermoplastic components are assembled with one or more metallic multi-path conductor components. The thermoplastic component(s) and the metallic multi-path conductor component(s) are then compressed together using a fixture or mold while the conductors are heated by inductive methods, Ohmic heating, or laser absorption. The heat generated within the conductors will reflow the thermoplastic material local to the conductors, resulting in a fused, rigid sub-assembly incorporating the internal electrical components. This sub-assembly will ensure proper positioning of the internal conductor components in the subsequent casting or overmolding operations necessary to complete the IPG header. 
         [0015]    In one embodiment, the thermoplastic-conductor subassembly starts out as two independent support structures, namely, a first molded split web and a second molded split web, each of which are made with conventional thermoplastic injection molding techniques. The first molded split web is then placed into a first pressure platen, and the second molded split web is placed into a second pressure platen. The conductor elements are then placed between the first and second molded split webs and, more specifically, in one embodiment, on top of one of the molded split webs. 
         [0016]    The positional accuracy of the placement of the conductor elements is dictated by features on the platen. The features will vary depending on conductor/antenna configuration (e.g., flat ribbons, antennas, and/or round wire). Once the conductor elements are in place between the two molded split webs and the two pressure platens holding the respective molded split webs, the two pressure platens are joined. The pressure platens are brought together at a predetermined force and the conductors (e.g., flat ribbons, antennas, and/or round wire) are heated by inductive methods, Ohmic heating (e.g., passing current), laser energy, or other heating methods. 
         [0017]    In one embodiment for applying electrical current to the conductors to induce Ohmic heating, contacts are made by pogo pins on one pressure platen, which are then connected to a power supply. Additional circuitry or controlling elements as known in the art can be used to ensure proper current and voltage to each conductive element. No matter whether Ohmic, inductive, or laser heating methods are used, the resulting elevated temperature softens the material surrounding the conductors while the pressure forces the materials to come in contact with one another, fusing the two molded split webs together and encapsulating the conductor(s) and/or antennas. After the heating is turned off and the resulting thermoplastic-conductor subassembly has cooled, the platens are opened and the thermoplastic-conductor subassembly can be removed. 
         [0018]    In one embodiment of a method of fabricating a thermoplastic-conductor subassembly for IPG headers, the method includes fusing a single piece thermoplastic structure to conductor elements to create the thermoplastic conductor subassembly. The thermoplastic material, although fused to the conductor elements, may or may not completely encapsulate the conductor elements. 
         [0019]    A single injection molded plate made of a thermoplastic, such as, for example, TECOTHANE, PELLETHANE, BIONATE, ELASTHANE, or etc., is provided. The conductor elements are welded to their respective ring and tip connector blocks. The thermoplastic plate is placed in intimate contact with the conductor elements and/or portions of the blocks. Application of pressure platens or other fixtures may be employed to ensure the intimate contact. The metal conductors are then heated by, for example, inductive, Ohmic, laser, or other heating processes in order to locally melt the thermoplastic plate, bonding it to the conductor elements and/or portions of the blocks. The resulting fused thermoplastic-conductor subassembly ensures no movement of the conductors during subsequent overmolding by conventional injection molding or casting operations necessary to complete the header. 
         [0020]    While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosure. As will be realized, the invention is capable of modifications in various aspects, all without departing from the spirit and scope of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is an isometric view of a proximal end portion (i.e., lead connector end) of a conventional transvenous bipolar pacing lead. 
           [0022]      FIG. 2  is an isometric view of a cardiac pacemaker/defibrillator unit (i.e., implantable pulse generator (IPG)) incorporating connector junctions or terminals for communication with one or more electrodes. 
           [0023]      FIG. 3  is an isometric view of a representative header. 
           [0024]      FIGS. 4A and 4B  are opposite isometric views of a representative connector assembly used with the header of  FIG. 3  to form a header connector assembly. 
           [0025]      FIG. 5  is an isometric view of a fused thermoplastic-conductor subassembly. 
           [0026]      FIG. 6  is a flow chart outlining a method of manufacturing the fused thermoplastic-conductor subassembly of  FIG. 5 . 
           [0027]      FIG. 7  is the same view as  FIG. 5 , except the thermoplastic structure of  FIG. 5  is in the form of two split webs that are positioned on either side of the conductor elements to be fused together about the conductor elements. 
           [0028]      FIG. 8  is the same view as  FIG. 7 , except further along in the manufacturing process outline in  FIG. 6  and wherein pressure platens have been introduced to compress together the conductor elements and the thermoplastic split webs. 
           [0029]      FIG. 9  is an isometric view of an example fusing system that melts or reflows the thermoplastic material of the opposed split webs while the opposed pressure platens are compressing the opposed split webs and the conductor elements together to cause the split webs and the conductor elements to fuse together. 
           [0030]      FIG. 10  is an isometric view of another fused thermoplastic-conductor subassembly  65 . 
           [0031]      FIG. 11  is a flow chart outlining a method of manufacturing the fused thermoplastic-conductor subassembly of  FIG. 10 . 
           [0032]      FIG. 12  is the same view as  FIG. 10 , except the thermoplastic structure has yet to be fused to the conductor elements. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Implementations of the present disclosure involve an implantable electronic device (IED) such as an implantable cardiac monitor (ICM) or an implantable pulse generator (IPG). The IPG administers electrotherapy or other neurostimulation via an implantable lead having a lead connector end on a proximal end of the implantable lead. The IPG includes a housing or can and a connector assembly enclosed in a header to form a header connector assembly that is coupled to the housing or can. The header connector assembly has at least one lead connector receiving bore or receptacle that includes electrical contacts of the connector assembly that make electrical contact with corresponding electrical terminals on the lead connector end on the proximal end of the implantable lead when the lead connector end is plugged into or otherwise received in the lead connector receiving bore or receptacle. Via the electrical connection between the corresponding electrical terminals of the lead connector end and the electrical contacts of the lead connector receiving bore, electrical signals can be administered from the IPG and through the lead to patient tissue. Similarly, but in reverse, electrical signals originating in patient tissue can travel via the lead to the IPG to be sensed at the IPG. 
         [0034]    The ICM is similar to the IPG in that it also includes a housing or can and a header. However, unlike the IPG, the ICM does not attach to leads and the ICM simply monitors electrical signals and does not administer therapy. 
         [0035]    The implantable electronic device configurations and methods of assembly disclosed herein are advantageous for at least the reason that they save costs and provide improvements to quality control. Specifically, the implantable electronic devices disclosed herein employ a fused thermoplastic-conductor subassembly  65  that maintains a desired spacing between the conductor elements  64  of the subassembly  64 . This desired spacing is a preferred spacing for assembling the connector assembly  42  into the header  40  to form the header connector assembly  22 . 
         [0036]    Before beginning a detailed discussion of fused thermoplastic-conductor subassemblies  65  and the corresponding methods of manufacture, a general discussion is first given regarding features of a common lead connector end at the proximal end of an implantable medical lead followed by a general discussion of the features of an IPG. While the following discussion of the implantable electronic device is given in the context on an IPG, it can be readily understood by those of skill in the art that the discussion is applicable to an ICM for the pertinent aspects of this disclosure. 
       A. Overview of Common Lead Connector End and IPG 
       [0037]      FIG. 1  shows a proximal end portion  10  of a conventional transvenous, bipolar pacing lead, but is generally representative of any type of implantable lead whether in the cardiac, pain management or other medical treatment space. The diameter of such a lead may be made a sufficiently small diameter to facilitate the lead&#39;s implantation into small veins such as those found in the coronary sinus region of the heart and to allow implantation of a plurality of leads into a single vessel for multi-site or multi-chamber pacing. It should be understood, however, that other lead designs may be used, for example, multipolar leads have proximal ends portions that are bifurcated, trifurcated or have other branched configurations. While the lead whose proximal end is shown in  FIG. 1  is of the bipolar variety, there are unipolar leads that carry but a single electrode, and multipolar leads that have more than two electrodes. 
         [0038]    As is well known in the art, bipolar coaxial leads typically consists of a tubular housing of a biocompatible, biostable insulating material containing an inner multifilar conductor coil that is surrounded by an inner insulating tube. The inner conductor coil is connected to a tip electrode on the distal end of the lead. The inner insulating tube is surrounded by a separate, outer multifilar conductor coil that is also enclosed within the tubular housing. The outer conductor coil is connected to an anodal ring electrode along the distal end portion of the lead. The inner insulation is intended to electrically isolate the two conductor coils preventing any internal electrical short circuit, while the housing protects the entire lead from the intrusion of body fluids. These insulating materials are typically either silicone rubber or polyurethane. More recently, there have been introduced bipolar leads in which multifilar cable conductors contained within multilumen housings are substituted for the conductor coils in order to reduce even further the overall diameter of the lead. 
         [0039]    The proximal lead end portion  10  shown in  FIG. 1  includes a lead connector end  11  that conforms to the IS-1 standard, comprising a pair of coaxial spaced-apart electrical terminals including a tip terminal  12  and a ring terminal  14 . The tip terminal  12  is electrically connected by means of the inner conductor coil to the tip electrode at the distal end of the lead, while the ring terminal  14  is electrically connected to the anodal ring electrode by means of the outer conductor coil. The tip and ring terminals of the lead connector end may each be engaged by a conductive garter spring contact or other resilient electrical contact element in a corresponding lead connector receiving bore of the header, the resilient electrical contact element being carried by a connector assembly enclosed in the header as described below. The lead connector end  11  on the proximal lead end portion  10  further comprises spaced-apart pairs of seal rings  16  for abutting against in a fluid-sealing manner the inner circumferential surface of the lead connector receiving bore of the header, thereby preventing body fluids from reaching the electrical terminals and contacts when the lead connector end  11  is plugged into the corresponding lead connector receiving bore. With the lead connector end  11  of the lead inserted in the lead connector receiving bore of the header and connector assembly, the tip and ring terminals  12  and  14  are electrically coupled via the contacts of the connector assembly and a feedthru to the electronic circuits within the hermetically sealed housing of the IPG (e.g., cardiac pacemaker, ICD, or other implantable tissue stimulation and/or sensing device such as those used in pain management, etc.). 
         [0040]      FIG. 2  shows a multi-site or multi-chamber cardiac pacemaker/defibrillator unit that is generally representative of any type of IPG  20  incorporating a header connector assembly  22  coupled to a housing  24 . The header connector assembly  22  includes a header  40  enclosing a connector assembly  42 , both of which are depicted respectively in  FIGS. 3, 4A and 4B  discussed below. The IPG  20  is of a conventional design, including a hermetically sealed housing  24 , which is also known as a can or casing. The housing  24  encloses the electronic components of the IPG  20  with the header connector assembly  22  mounted along a top surface  26  of the housing  24 . 
         [0041]      FIG. 2  illustrates that, in some embodiments, the header connector assembly  22  may include four or more lead connector receiving bores or receptacles  30 ,  31 ,  32  and  33  for receiving the lead connector ends of four implantable leads.  FIG. 2  also shows the proximal end portion  10  of a lead, wherein the lead connector end on the proximal end portion  10  of the lead is received in a corresponding receptacle  32 . In other embodiments, the header connector assembly  22  includes two receptacles comprising a single pair of receptacles (i.e., receptacles  30  and  33 ) for receiving the proximal ends of leads such as, for example, conventional bipolar leads and/or conventional cardioverting and/or defibrillating leads. 
         [0042]      FIG. 3  is an isometric view of a representative header  40 , and  FIGS. 4A and 4B  are opposite isometric views of a representative connector assembly  42 . Unlike the header connector assembly  22  of  FIG. 2 , the header  40  of  FIG. 3  only has a single pair of receptacles  30  and  33 . However, in other embodiments, the header  40  of  FIG. 3  may have two or more pairs of receptacles similar to the embodiment of  FIG. 2 . 
         [0043]    As illustrated in  FIGS. 4A and 4B , the connector assembly  42  includes tip blocks  44  and ring blocks  46 . The ring blocks  46  include spring contacts  48 . Each electrical block  44  and  46  of the connector assembly  42  serves as an electrical contact of the connector assembly  42 . Thus, as can be understood from  FIGS. 1-4B , each tip block  44  is configured to receive and make electrical contact with the tip terminal  12  of a lead connector end  11  received in the corresponding receptacle  30 ,  33  of the header  40 . Similarly, each ring block  46  is configured to receive and make electrical contact with the ring terminal  14  of a lead connector end  11  received in the corresponding receptacle  30 ,  33  of the header  40 . While the connector assembly  42  of  FIGS. 4A and 4B  is of an IS-1 configuration, other configurations (e.g., IS-4, etc.) are used in other embodiments. While the connector assembly  42  of  FIGS. 4A and 4B  only depicts two pairs of blocks  44 ,  46 , in other embodiments where the header includes more than a single pair of receptacles  30 ,  33  (e.g., two pairs of receptacles  30 ,  31 ,  32 ,  33  as indicated in  FIG. 2 ), the connector assembly  42  will have a four pairs of blocks  44 ,  46 . 
         [0044]    As shown in  FIGS. 4A and 4B , the connector assembly  42  also includes a host of electrically conductive components including an antenna  48 , a an RF anchor tab  50 , an RF pin tab  52 , an A-tip tab  54 , an A-ring tab  56 , an RV-ring tab  58 , an RV-tip tab  60 , and a ribbon carrier  62  and other conductors  64  that extend between the various tabs and their respective electrical contacts of the connector assembly or other components thereof. In other words, as can be understood from  FIGS. 4A and 4B , electrical conductor elements (e.g., wires, traces, or other electrical conductors)  64  extend between the electrical blocks  44 ,  46  and the respective tabs  50 ,  52 ,  54 ,  56 ,  58  and  60 . Also, such conductor elements  64  may form the antenna  48  and the ribbon carrier  62 . 
         [0045]    The various tabs are welded to corresponding terminals extending from circuitry of the IPG  20  contained in the housing  24  of the IPG  20  depicted in  FIG. 2  when the header connector assembly  22  is joined with the housing  24  to form the IPG  20 . The connector assembly  42  is manufactured of materials and via methods known in the Industry. The connector assembly  42  is cast in place, injected molded or otherwise installed into the header  40  to form the header connector assembly  22  of  FIG. 2 , which can be considered a first module that is then attached via a backfill or other process to a second module in the form of the housing  24 . In other words, the header connector assembly  22  (i.e., first module) is attached via a backfill or other process to the housing  24  (i.e., the second module) to form the IPG  20 . 
         [0046]    In order for the IPG  20  to have proper functionality when implanted, certain spacing between the electrically conductive components of the connector assembly  42  should be maintained during the installation of the connector assembly  42  into the header  40 . A fused thermoplastic-conductor subassembly  65  can be employed to maintain the desired spacing. This thermoplastic-conductor subassembly  65  and its method of manufacture and use will now be discussed in detail. 
       B. Thermoplastic-Conductor Subassemblies and Methods of Manufacture and Use 
       [0047]      FIG. 5  is an Isometric view of a fused thermoplastic-conductor subassembly  65 . As illustrated in  FIG. 5 , the subassembly  65  includes the electrical conductor elements (e.g., wires, traces, or other electrical conductors)  64  associated with the antenna  48 , RF anchor tab  50 , RF pin tab  52 , A-tip tab  54 , A-ring tab  56 , RV-ring tab  58 , RV-tip tab  60 , and ribbon carrier  62  of the connector assembly  42  of  FIGS. 4A-4B , plus a thermoplastic structure  66  encapsulating portions of the conductor elements  64  at certain locations of the conductor elements  64  and thereby maintaining a desired spacing between the conductor elements  64 . The desired spacing between the conductor elements  64  that is maintained via the thermoplastic structure  66  is one that is preferred during the manufacturing of the connector assembly  42  from the conductor elements  64  and the combining of the connector assembly  42  with the header  40  of the header connector assembly  22  to form the header connector assembly  22 , the combining of the connector assembly  42  with the header  40  involving a backfilling process, an overmolding process, an injection molding process or another manufacturing process. 
         [0048]    To begin a discussion of the manufacture of the fused thermoplastic-conductor subassembly  65  of  FIG. 5 , reference is made to  FIGS. 6 and 7 .  FIG. 6  is a flow chart outlining the manufacturing process, and  FIG. 7  is the same view as  FIG. 5 , except the thermoplastic structure  66  of  FIG. 5  is in the form of two split webs  66 A,  66 B that are positioned on either side of the conductor elements  64  to be fused together about the conductor elements  64  as shown in  FIG. 5  and as discussed below. As can be understood from  FIGS. 5 and 7 , the conductor elements  64  are initially maintained in position relative to each other via regions or bases  68  of excess or scrap conductive material from which the conductor elements  64  are printed, etched, stamped, etc. These excess or scrap regions or bases  68  are removed from the conductor elements  64  at separation lines  70  at a point in the assembly subsequent to the fusing of the webs  66 A,  66 B about the conductor elements  64 . For purposes of this discussion, when the conductor elements  64  are positioned relative to each other via the attached regions or bases  68  prior to the regions or bases  68  being removed from the conductor elements  64 , the combined conductor elements  64  and regions or bases  68  are referred to herein as a conductor-base assemblies  72 . 
         [0049]    As can be understood from  FIGS. 6 and 7 , in one embodiment, the conductor-base assemblies  72  are positioned between the opposed split webs  66 A,  66 B [block  100 ]. More specifically, the conductor-base assemblies  72  are positioned between the opposed split webs  66 A,  66 B such that the conductor elements  64  are located between the opposed split webs and will be sandwiched between split webs when the split webs are brought together. The split webs  66 A,  66 B may be formed of thermoplastic materials such as, for example, TECOTHANE, PELLETHANE, BIONATE, ELASTHANE, or etc. 
         [0050]    As illustrated in  FIG. 8 , which is the same view as  FIG. 7 , except further along in the process, the opposed split webs  66 A,  66 B and the conductor-base assemblies  72  are located between opposed pressure platens  76 A,  76 B of a mold or fixture [block  110 ]. The opposed split webs  66 A,  66 B and the conductor-base assemblies  72  are then sandwiched between the pressure platens  76 A,  76 B [block  120 ]. The thermoplastic material of the opposed split webs  66 A,  66 B is melted or caused to reflow about the conductor elements  64 , thereby imbedding the conductor elements  64  in the thermoplastic material in at least a few locations on the conductor elements and causing the opposed split webs to fuse to each other and with the conductor elements [block  130 ]. The melting or reflowing of the thermoplastic material of the opposed split webs can be brought about via the application of energy to the thermoplastic via inductive heating, Ohmic heating, laser absorption, or other heating methods. The heating of the thermoplastic can be via direct application of energy to the thermoplastic or via indirect application of energy to the thermoplastic such as, for example, direct application of energy to the conductor elements  64 , which in turn melts or reflow the thermoplastic at those areas of contact between the conductor elements and the thermoplastic. 
         [0051]    In one embodiment, the heating, and the associated melting or reflowing of the thermoplastic material of the opposed split webs, can occur immediately prior to the opposed split webs  66 A,  66 B being compressed together about the conductor elements  64  of the conductor-base assemblies  72  by the pressure platens  76 A,  76 B being compressed together. 
         [0052]    In one embodiment, the heating, and the associated melting or reflowing of the thermoplastic material of the opposed split webs, can occur while the opposed split webs  66 A,  66 B are being compressed together about the conductor elements  64  of the conductor-base assemblies  72  by the pressure platens  76 A,  76 B being compressed together. 
         [0053]      FIG. 9  is an Isometric view of an example fusing system  78  that melts or reflows the thermoplastic material of the opposed split webs  66 A,  66 B while the opposed pressure platens  76 A,  76 B are compressing the opposed split webs and the conductor elements  64  of the conductor-base assemblies  72  together to cause the split webs and the conductor elements to fuse together and form the fused thermoplastic-conductor subassembly  65  of  FIG. 5 . As shown in  FIG. 9 , the system  78  includes a power supply  80  electrically coupled via electrical conductors  82  to pogo pins  84  that extend through the upper pressure platen  76 A. Each pogo pin  84  makes electrical contact with a respective common or ground contact  86  on a base  68  of a conductor-base assembly  72  or a power contact  88  on a specific conductor element  64  of the conductor-base assembly  72 . Via the power supply and the network of conductors electrically coupled to the base  68  and conductor elements  64  of a conductor-base assembly  72 , the conductor-base assembly  72  can be heated via Ohmic heating while the pressure platens  76 A,  76 B compressively sandwich together the thermoplastic split webs  66 A,  66 B about the conductor elements  64 . The elevated temperature of the conductor elements  64  provides the heat to melt or reflow the thermoplastic material of the split webs to cause the thermoplastic material to fuse about the conductor elements  64  and the split webs  66 A,  66 B to fuse together, thereby forming the fused thermoplastic-conductor subassembly  65  of  FIG. 5 . 
         [0054]    Once the thermoplastic material has sufficiently cooled, the fused thermoplastic-conductor subassembly  65  of  FIG. 5  can be removed from the system  78  of  FIG. 9  [block  140 ]. The blocks  44 ,  46  can then welded to the conductor elements  64  to form the connector assembly  42  of  FIGS. 4A and 4B , after which the connector assembly  42  can be assembled into the header  40  via casting, injection molding, or other methods to form the header connector assembly  22  of  FIG. 2 . The header connector assembly is coupled to the housing  24  of the IPG  20  via methods known in the art. 
         [0055]    While, as discussed above with respect to  FIGS. 5-9 , the fused thermoplastic-conductor subassembly  65  may be the result of a manufacturing process wherein the conductor elements  64  are sandwiched between a pair of opposed split webs  66 A,  66 B that are fused together and about the conductor elements, in other embodiments, the fused thermoplastic subassembly  65  may be manufactured via other methods and have other configurations. For example, as depicted in  FIG. 10 , which is an isometric view of another fused thermoplastic-conductor subassembly  65 , the subassembly  65  includes blocks  44 ,  46 , electrical conductor elements (e.g., wires, traces, or other electrical conductors)  64  associated with the antenna  48 , RF anchor tab  50 , RF pin tab  52 , A-tip tab  54 , A-ring tab  56 , RV-ring tab  58 , RV-tip tab  60 , and ribbon carrier  62  of the connector assembly  42  of  FIGS. 4A-4B , plus a thermoplastic structure  66  fused with portions of the conductor elements  64  at certain locations of the conductor elements  64  and, in some instances, the blocks  44 ,  46 . The thermoplastic structure  66  of this embodiment may be in the form of a single thermoplastic plate or sheet. In one embodiment of this subassembly  65 , because the blocks  44 ,  46  are welded to the conductor elements  64  prior to the thermoplastic being fused to the conductor elements, the blocks  44 ,  46  are included, eliminating the need for subsequent attachment. 
         [0056]    The fusing of the thermoplastic structure  66  with the conductor elements and blocks maintains a desired spacing between the conductor elements  64  and blocks  44 ,  46 . This desired spacing is one that is preferred during the manufacturing of the connector assembly  42  from the conductor elements  64  and the combining of the connector assembly  42  with the header  40  of the header connector assembly  22  to form the header connector assembly  22 , the combining of the connector assembly  42  with the header  40  involving a backfilling process, an overmolding process, an injection molding process or another manufacturing process. 
         [0057]    To begin a discussion of the manufacture of the fused thermoplastic-conductor subassembly  65  of  FIG. 10 , reference is made to  FIGS. 11 and 12 .  FIG. 11  is a flow chart outlining the manufacturing process, and  FIG. 12  is the same view as  FIG. 10 , except the thermoplastic structure  66  has yet to be fused to the conductor elements  64 . As can be understood from  FIGS. 10 and 12 , the conductor elements  64  are initially maintained in position relative to each other via regions or bases  68  of excess or scrap conductive material from which the conductor elements  64  are printed, etched, stamped, etc. These excess or scrap regions or bases  68  are removed from the conductor elements  64  at separation lines  70  at a point in the assembly subsequent to the fusing of the webs  66 A,  66 B about the conductor elements  64 . For purposes of this discussion, when the conductor elements  64  are positioned relative to each other via the attached regions or bases  68  prior to the regions or bases  68  being removed from the conductor elements  64 , the combined conductor elements  64  and regions or bases  68  are referred to herein as a conductor-base assemblies  72 . 
         [0058]    As can be understood from  FIGS. 11 and 12 , in one embodiment, the conductor-base assemblies  72  are positioned adjacent the thermoplastic structure  66  such that the thermoplastic structure is in intimate contact with the conductor elements  64  and/or portions of the blocks  44 ,  46  [block  200 ]. The thermoplastic structure  66  may be formed of thermoplastic materials such as, for example, TECOTHANE, PELLETHANE, BIONATE, ELASTHANE, or etc. 
         [0059]    Optionally and similar to as discussed above with respect to  FIGS. 5-9 , pressure platens or other fixtures may be employed to maintain the intimate contact between the thermoplastic structure  66  and the conductor elements  64  and/or portions of the blocks  44 ,  46 . The thermoplastic material of the thermoplastic structure  66  is melted or caused to reflow about the conductor elements  64 , thereby fusing, if not imbedding, the conductor elements  64  in the thermoplastic material in at least a few locations on the conductor elements [block  210 ]. The melting or reflowing of the thermoplastic material of the thermoplastic structure  66  can be brought about via the application of energy to the thermoplastic via inductive heating, Ohmic heating, laser absorption, or other heating methods. The heating of the thermoplastic can be via direct application of energy to the thermoplastic or via indirect application of energy to the thermoplastic such as, for example, direct application of energy to the conductor elements  64 , which in turn melts or reflow the thermoplastic at those areas of contact between the conductor elements and the thermoplastic. 
         [0060]    Once the thermoplastic material has sufficiently cooled, the fused thermoplastic-conductor subassembly  65  of  FIG. 10  can be readied for combination with the header  40  via casting, injection molding, or other methods to form the header connector assembly  22  of  FIG. 2  [block  220 ]. The header connector assembly is coupled to the housing  24  of the IPG  20  via methods known in the art. 
         [0061]    As mentioned above with respect to the embodiment of  FIGS. 5-9  and the embodiment of  FIGS. 10-12 , the thermoplastic material  66  may be heated by inductive heating or by passing a current through the conductor elements  64  (Ohmic heating). Due to the use of electrical power, any compression platens  76 A,  76 B or other fixtures will be made of heat-resistant, non-conductive materials, such as, for example, polyetheretherketone (“PEEK”), Polytetrafluoroethylene (“PTFE”), ceramic, or etc. 
         [0062]    In the case of inductive heating, an AC magnetic field is generated surrounding the conductor elements  64  to induce electrical eddy currents which heat the conductor elements  64 . The methods for generating such a magnetic field take into consideration the complicated geometry of the conductor elements  64 . Magnetic field generation can be incorporated locally into the platens  76 A,  76 B or by a device external to the platen assembly. 
         [0063]    In the case of Ohmic heating, an AC or DC electrical current is passed through each conductive path of the conductor elements  64 . Energy lost due to resistance of the material of the conductor elements generates heat. The temperature is controlled by voltage and current. Because there are multiple conductive paths, Ohmic heating will employ multiple connections. The base  68  of the conductor-base assembly  72  may be used as a common connection, and an electrical connection with the termination end of each conductor element  64  is made. 
         [0064]    Also as mentioned above with respect to the embodiment of  FIGS. 5-9  and the embodiment of  FIGS. 10-12 , the thermoplastic material  66  may be heated by the application of laser energy that is absorbed primarily by the conductor elements  64 . In its simplest application, the laser energy can be directly focused onto the metal (e.g. titanium) forming the conductor elements  64 . Because most clear thermoplastics have minimal absorption of 1 um to 2 um laser energy, lasers of these wavelengths can be directed through the thermoplastic plate and onto the titanium below. The laser energy can also be passed through glass or other optically clear platens or other fixtures, as needed. Surface roughed conductor elements  64  will absorb laser energy much more effectively. 
         [0065]    Regardless of how the fused thermoplastic-conductor subassembly  65  manufactured, it will need to be incorporated into a final device  20 . In one embodiment, the final step is a header over-molding process which may also incorporate additional mechanical components (e.g. header blocks, connectors, etc.). Final header over-molding can be done by epoxy-based cast in place methods as a stand-alone “premolded header” or directly onto the titanium device can  24 . A “premolded” header can also be prepared by thermoplastic injection molding methods, where the fused thermoplastic-conductor subassembly  65  is inserted into the mold cavity prior to injection molding. If the header  40  is “premolded”, it will have to be attached to the titanium can  24  using adhesives and possibly mechanical anchors. Electrical connections will also have to be made by welding or an appropriate connector. 
         [0066]    The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements and methods which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present invention. From the above description and drawings, it will be understood by those of ordinary skill in the art that the particular embodiments shown and described are for purposes of illustrations only and are not intended to limit the scope of the present invention. References to details of particular embodiments are not intended to limit the scope of the invention.