Abstract:
An embodiment disclosed herein relates to a communications module. The communications module includes a body composed of a plastic resin and a plurality of conductive traces and contact pads defined on a portion of a surface of the body. The module also includes at least one substantially vertical ridge defined on the body surface, and at least one pocket defined on the body suitable for receiving an electronic component. The communications module may also include a body composed of a plastic resin and conductive features defined on a surface of the body configured to render the communications module operable without implementing a printed circuit board as part of the body. Additional embodiments relate to systems and methods for attaching one or more optical transmit assemblies to the communications module and for electrically connecting conductive traces in a temporary fashion on the surface of the body of the communications module.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/870,331, filed Dec. 15, 2006, U.S. Provisional Application No. 60/870,334, filed Dec. 15, 2006, and U.S. Provisional Application No. 60/870,338, filed Dec. 15, 2006, all of which are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. The Field of the Invention 
         [0003]    The present invention generally relates to communications modules. In particular, the present invention relates to a communications module, such as an optical transceiver module, that is integrally fabricated so as to reduce part count and simplify construction and design. 
         [0004]    2. The Relevant Technology 
         [0005]    Traditionally designed optical transceiver modules typically include several components, including one or more optical subassemblies, a printed circuit board with associated electronic circuitry, and a shell supporting the printed circuit board. Though proven, this design nevertheless compels various compromises to be tolerated, due to limitations inherent in the above-mentioned components and their respective interconnections. In light of this, a need exists in the art for a communications module, such as an optical transceiver module, that includes improvements that provide simplification of design and part count reduction while improving device reliability. 
       BRIEF SUMMARY 
       [0006]    An embodiment disclosed herein relates to a communications module. The communications module includes a body composed of a plastic resin and a plurality of conductive traces and contact pads defined on a portion of a surface of the body. The module also includes at least one substantially vertical ridge defined on the body surface, and at least one pocket defined on the body suitable for receiving an electronic component. 
         [0007]    An additional embodiment disclosed herein relates to a communications module. The communications module includes a body composed of a plastic resin and one or more conductive features defined on a surface of the body. The one or more conductive features are configured to render the communications module operable without implementing a printed circuit board as part of the body. 
         [0008]    A further embodiment disclosed herein relates to a system for electrically connecting at least one optical subassembly to an optical transceiver module. The optical transceiver module has a molded body and conductive features defined on portions of the molded body. The system comprises an interconnect portion integrally formed with the molded body including: a plurality of holes defined on a front wall of the molded body, the holes being configured to each receive a corresponding one of a plurality of leads extending from an optical subassembly, and a plurality of lead seats each in communication with a corresponding one of the plurality of holes, each lead seat configured such that the lead received by the corresponding hole is in electrical communication with the lead seat. The system also includes a plurality of traces defined on the molded body that each electrically connect with a corresponding one of the lead seats. 
         [0009]    Another embodiment disclosed herein relates to a method for electrically connecting conductive traces in a temporary fashion. The traces are included on a surface of a molded body of an optical transceiver module. The method includes defining a plurality of trace interconnection features as extended portions on a surface of the molded body such that the trace interconnection features are interposed between the traces. The method also includes applying a conductive material to each of the trace interconnection features such that the trace interconnection features electrically interconnect the traces to one another. The method further includes, when electrical interconnection of the traces is no longer needed, altering a structure of each of the trace interconnection features such that the traces are no longer electrically interconnected by the trace interconnection features. 
         [0010]    This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
         [0011]    Additional features and advantages will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the teaching herein. The features and advantages of the teaching herein may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    To further clarify the above and other advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
           [0013]      FIG. 1A  is a perspective top view of portions a molded communications module, according to one embodiment of the present invention; 
           [0014]      FIG. 1B  is a perspective bottom view of the molded communications module of  FIG. 1A ; 
           [0015]      FIG. 2  is a perspective top view of the molded communications module of  FIG. 1A , having a pair of optical subassemblies operably attached thereto; 
           [0016]      FIG. 3  is a close-up perspective top view of the molded communications module of  FIG. 1A , including an integrated circuit chip included thereon; 
           [0017]      FIG. 4  is an exploded, perspective top view of the molded communications module of  FIG. 2  including the two optical subassemblies, according to one embodiment of the present invention; 
           [0018]      FIG. 5  is another exploded, perspective top view of the molded communications module shown in  FIG. 4 ; 
           [0019]      FIG. 6  is a perspective bottom view of the molded communications module of  FIG. 4  in an assembled state, according to one embodiment of the present invention; 
           [0020]      FIG. 7  is a top perspective view of the molded communications module of  FIG. 6  in its assembled state; 
           [0021]      FIG. 8  is a perspective bottom view of the molded communications module according to one embodiment of the present invention; 
           [0022]      FIGS. 9A-9C  are cross sectional end views of possible shapes of trace interconnection features configured in accordance with embodiments of the present invention; 
           [0023]      FIG. 10  is a close-up perspective view of the molded communications module of  FIG. 3 , including the trace interconnection features in a second state according to one embodiment of the present invention; 
           [0024]      FIG. 11A  is a perspective view of trace interconnection features in a first state according to another embodiment of the present invention; 
           [0025]      FIG. 11B  is a perspective view of trace interconnection features in a second state according to one embodiment; 
           [0026]      FIG. 11C  is a perspective cutaway view of the trace interconnection features of  FIG. 11B ; and 
           [0027]      FIGS. 12A-12C  are close-up perspective views of a molded communications module, including trace interconnection features configured together with “punch-out” features in accordance with yet another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Reference will now be made to figures wherein like structures will be provided with like reference designations. It is understood that the drawings are diagrammatic and schematic representations of exemplary embodiments of the invention, and are not limiting of the present invention nor are they necessarily drawn to scale. It is also understood that reference to a “first”, or a “second” etc. element (such as a first and second interconnect portions) in this description and in the claims is meant to distinguish one element from another and is not meant to imply sequential ordering unless explicitly stated. 
         [0029]      FIGS. 1A-12C  depict various features of embodiments of the present invention, which are generally directed to a communications module for use in transmitting and receiving data signals in a communications network. In particular, a communications module implemented as an optical transceiver module is disclosed. The optical transceiver module includes a molded integral body and electronic component surface designed to substantially simplify transceiver design and reduce part count. Because of its simplified design, the molded transceiver is highly stable and efficiently produced, thereby increasing part yield during manufacture. 
       1. Example Molded Communications Module 
       [0030]    Reference is first made to  FIGS. 1A ,  1 B, and  2 , which depict various details regarding features of the present invention, according to one embodiment. These figures show one type of communications module that can benefit from the teachings of the present invention. In particular, an optical transceiver module (“transceiver”), generally designated at  100 , is shown as an exemplary communications module including aspects of one embodiment of the present invention. 
         [0031]    As shown, the transceiver  100  is implemented as having a form factor and configuration conforming to a Small Form Factor Pluggable (“SFP”) standard, as defined by applicable Multi-Source Agreements (“MSAs”) standard in the industry. However, it should be noted that transceivers and other communications modules that differ in form factor, operational configuration, or other aspects can also benefit from the principles discussed herein. Indeed, modules such as 10 Gigabit Small Form Factor Pluggable (“XFP”) transceivers having varying form factors and data rates can also employ features of the embodiments to be described herein. The following discussion is therefore not meant to limit the scope of the present invention in any way. 
         [0032]    As shown, the transceiver  100  includes a body  110  that is formed by standard injection molding or other suitable molding process. As such, the transceiver body is also referred to herein as a “molded module.” As will be described, the body  110  serves multiple purposes within the transceiver  100  that were formerly performed by multiple components, and as such simplifies transceiver design by serving as an integrated component. 
         [0033]    The transceiver body  110  is composed of a suitable material to enable the formation of conductive features on the body in the manner described below. In one embodiment, the body  110  is composed of a plastic resin, such as a liquid crystal polymer, having a catalyst intermixed therewith. In one embodiment, the catalyst is composed substantially of palladium, but other suitable materials offering the same functionality could alternatively be used. As mentioned, this material composition for the transceiver body enables conductive features to be defined on the body, as will be described further below. 
         [0034]    The transceiver body  110  further includes a top body surface  110 A and bottom body surface  110 B, and defines a front end  112  and back end  114 . The back portion of the body  110  proximate the back end  114  defines an edge connector  116  that enables the transceiver  100  to operably connect with a host device (not shown). The edge connector  116  itself defines a top surface  116 A and bottom surface  116 B. Note that the edge connector  116  has a height that is relatively less than that of other portions of the body  110 , in conformance with industry-defined standards for such an interface. 
         [0035]    As seen in  FIG. 2 , the transceiver  100  includes a pair of optical subassemblies that each operably connect with connectorized optical fibers. In detail, a transmitter optical subassembly (“TOSA”)  118  and receiver optical subassembly (“ROSA”)  120  are included in the transceiver  100  and are shown in operable communication with the transceiver body  110  in  FIG. 2 . The TOSA  118  operably connects with the transceiver body  110  via a TOSA interconnect portion  122  that extends beyond and between both the body top and bottom surfaces  110 A and  110 B, while the ROSA  120  operably connects with the transceiver body via a ROSA interconnect portion  124 , which extends beyond and between the body top and bottom surfaces. Further details regarding the particular modes of connection between the TOSA, ROSA, and the transceiver body are described in more detail to follow. 
         [0036]    Inspection of  FIGS. 1A-2  reveals that the present transceiver design differs from previously known designs in that a printed circuit board, traditionally included within a transceiver shell, is not present. Instead, the molded transceiver body integrally serves the functionality previously performed by the printed circuit board and shell. In particular, the conductive contact pads, traces, and electronic components traditionally found on a transceiver printed circuit board are now included on the top and bottom surfaces  110 A and  110 B of the transceiver body  110 . Further, the structure of the transceiver body  110  is configured such that it also performs the functionality traditionally performed by a discrete shell in housing the printed circuit board and other transceiver components. Thus, significant consolidation and integration of formerly discrete transceiver components is realized via the present transceiver configuration. Further, use of the present transceiver body enables the inclusion of various surface features and three-dimensional structures to be included thereon, as will be described. 
         [0037]    Together with  FIGS. 1A-2 , reference is now made to  FIG. 3 , showing various further details of the transceiver  100 . A plurality of contact pads  130  are included on both the top and bottom surfaces  116 A and B of the edge connector  116  for interfacing with corresponding pads or conductive features of the host device (not shown). Among these pads are disposed a first data signal pad pair  130 A and a second data signal pad pair  130 B that each facilitate the transfer of high speed data signals between the host device and the transceiver  100 . Additionally, a plurality of conductive traces  134  are also included on the transceiver body  110  and operably connect with corresponding contact pads  130  on both the top and bottom surfaces  116 A and B of the edge connector  116  to enable the transfer of various signals in the transceiver  100 . Among these traces are disposed a first data signal trace pair  134 A and a second data signal trace pair  134 B that each operably connect with the corresponding first or second data signal pad pairs  130 A or  130 B of the edge connector  116 . Also included are ground traces  134 C that operably connect with corresponding ground contact pads  130 C on the edge connector  116 . 
         [0038]    The conductive contact pads  130  and traces  134  are defined on the surface of the transceiver body  110  by a process known as laser direct structuring, wherein a guided laser is employed during transceiver body manufacture in etching the surfaces of the body  110  where conductive features such as the contact pads and traces are to be located. Laser etching in this manner removes several microns of the plastic resin body material at the surface thereof, which exposes and activates the palladium catalyst imbedded in the plastic resin. So prepared, placement of the body  110  in an electroless plating bath causes copper or other suitable component of the bath to adhere to the laser etched portions of the body, thereby forming the contact pads  130 , traces  134  and other conductive features described below on the body. 
         [0039]    Formation of conductive features on a catalyst-containing plastic resin using the laser direct structuring process as described above yields a product also known as and referred to herein as a “plastic circuit.” This process and technology is owned and licensed by LPKF Laser and Electronics AG, Germany, http://www.lpkf.com/. Products formed by this process are generally known as molded interconnect devices (“MID”s). 
         [0040]    Should the particular path, shape, or other configuration of the contact pads  130 , traces  134 , or other conductive features need to be altered for a transceiver body yet to be manufactured, the laser need simply be reprogrammed to etch the body surface in accordance with the desired change. In this way, reconfiguration of the conductive features of the transceiver body is readily achieved without significant expense or time. 
         [0041]    In accordance with embodiments of the present invention, the transceiver body  110  can be configured to include various surface features serving various purposes for the transceiver  100 . These surface features give the transceiver body  110  a three dimensional (“3-D”) aspect that is not possible with known transceivers and other communication modules employing standard printed circuit boards (“PCBs”). The transceiver body configured to include the 3-D features to be described below is also referred to herein as a “3-D MID.” 
         [0042]    A first 3-D feature is shown on the transceiver body  110  as a plurality of various body extensions  140  that are formed as a result of the injection molded design of the body. The body extensions  140  serve various purposes in connection with the structure and functionality of the transceiver  100 , such as providing structural bracing or spacing, and surfaces for engagement with a cover to provide a housing (not shown) for the transceiver, for instance. In one embodiment, the body extension  140  (seen in  FIG. 2 ) proximate the TOSA  118  and ROSA  120  can be plated with conductive material via the laser direct structuring or other suitable process in order to reduce or prevent the emission of EMI from the transceiver  100 . In other embodiments, other surfaces of the transceiver  100  can also be conductively plated to reduce EMI emission. 
         [0043]    Another 3-D feature of the transceiver body  110  is shown at  144 , wherein a hole, or via, is defined through the body so as to extend from the top body surface  110 A to the bottom surface  110 B. The via  144  enables signals transmitted on selected traces  134  to be transferred from one body surface to another, as best shown in  FIGS. 1A and 1B . Note that the interior surface of the via  144  is slanted with respect to the top and bottom body surfaces  110 A, B. This is to enable sufficient laser etching to be performed on the via  144  so that a conductive material may be applied thereto. Generally, the slant of such surfaces should be no greater than about 75 degrees from a plane define by the top or bottom body surface  110 A or  110 B. More generally, the slant is determined by the requirements of the particular laser etching equipment used. Note that many such vias can be defined in the transceiver body  110 . 
         [0044]    A component pocket  146  is defined on the top body surface  110 A, as best shown in  FIG. 1A , as yet another possible 3-D feature made possible by the transceiver body  110  configured in accordance with one embodiment. The component pocket  146  is sized and configured to receive therein an integrated circuit chip or other electronic or optoelectronic component. In the illustrated embodiment, an integrated laser driver/post amplifier/controller (“LDPA controller”)  150  is shown in  FIGS. 2 and 3  as residing within the component pocket  146 . 
         [0045]    The floor of the component pocket  146  includes a conductive pad  154  ( FIG. 1 ) that is configured to electrically connect with the LDPA controller  150 , either through wirebonds (not shown), an electrically conductive pad on the underside of the LDPA controller  150 , or other electrical connective scheme when it is disposed in the component pocket  146 . The conductive pad  154  in turn is electrically connected to one or more of the traces  134  that extend to the component pocket  146 , such as the ground traces  134 C in the present embodiment. The LDPA controller  150  is secured within the component pocket  146  with a conductive adhesive in one embodiment, or by solder paste or other suitable securing substance. 
         [0046]    Note that, because the component pocket  146  is sunken with respect to the top body surface  110 A, a top surface of the LDPA controller  150  when placed in the pocket is positioned substantially level with the top body surface  110 A. This enables electrical connections of minimum length to be established between selected traces  134  that terminate at the component pocket  146  and conductive pads positioned on the LDPA controller  150 . These electrical connections in the present embodiment are achieved by the use of wire bonds (not shown). As improved signal transmission is achieved with wire bonds when the wire bond length is minimized, the minimization of length between the terminations of the traces  134  proximate the component pocket  146  and the pads of the LDPA controller  150  advantageously operates to improve signal transmission—especially high frequency signals—between the two structures. Once placement, securing, and wire bonding of the LDPA controller  150  within the component cavity  146  is complete, the controller can be covered with epoxy to prevent damage to the controller or wire bonds. 
         [0047]    Note that one or more component pockets  146  having varying sizes, depths, and particular configurations can be disposed at various locations on the top and bottom body surfaces  110 A/B to receive multiple components as may be needed for a particular application. Also, though shown here with an LDPA controller, any one of various different components may be placed in this or other component pockets defined on the molded transceiver body. Further, more than one component may be received in each component pocket. 
         [0048]    As best seen in  FIG. 2 , the molded transceiver body  110  includes a plurality of additional component pads  158  that, like the component pad  154  of the component pocket  146 , enable the electrical connection of various electronic components to the body. Such electronic components can include capacitors, resistors, etc. 
         [0049]    As yet another example of 3-D featuring of the molded transceiver body  110 , a plurality of vertical ridges  160  are defined on the body so as to enable conductive traces to be defined thereon. In particular, a first ridge  160 A having the data signal trace pair  134 A disposed thereon, and a second ridge  160 B having the data signal trace pair  134 B disposed thereon are shown. The traces of each pair  134 A and  134 B are disposed on opposing sides of the respective ridges  160 A and  160 B. This configuration enables the traces of each pair to effectively couple with one another, thereby controlling their respective impedance, i.e., creating a differential impedance known as “broadside coupling,” and preserving the quality of the data signals transmitted therethrough. Such a configuration compensates for the fact that no ground exists in the transceiver body  110  as would typically exist for coupling purposes in a standard printed circuit board. 
         [0050]    Two troughs  162  as additional 3-D features are included on the transceiver body, defined on the top surface  116 A of the edge connector  116  such that a back portion of each ridge  160 A and  160 B is positioned in the respective trough. So configured, the troughs  162  enable the ridges  160 A and  160 B to extend into the edge connector  116  in such a way as to not exceed the industry-defined 1 mm height restriction for this style of edge connector. Note that the rear termination of the troughs  162  corresponds with the point at which the data signal traces pairs  134 A and  134 B electrically connect with the corresponding data signal pads  130 A and  130 B, respectively. 
         [0051]    Yet another 3-D feature of the molded transceiver body  110  is a plurality of trace interconnection features  164  located at various points on the transceiver body. These trace interconnection features  164  are employed to temporarily interconnect the various traces  134  one with another during the transceiver manufacturing process. Once interconnection between the traces  134  is no longer needed, the trace interconnection features  164  can be modified such that trace interconnection is terminated. Further details regarding the trace interconnection features  164 , their structure and operation is described in more detail to follow. 
         [0052]    Further note that the traces  134  disposed on the transceiver body  110  can pass between the bottom and top body surfaces  110 A and  110 B around the edges of the transceiver body, such as at locations  166 . This is another feature not possible with standard printed circuit board technology. 
         [0053]    Note that the transceiver body  110  is not limited to a single thickness, as is common with known printed circuit boards, but rather can be configured to have various 3-D surface features and thicknesses as may be needed or desired for a particular application. Thus, instead of a 1 mm thick printed circuit board in accordance with the thickness required for the edge connector, the transceiver body can have a plurality of thicknesses and configurations along its length on either the top, bottom, or other surface thereof. 
         [0054]    A transceiver made in accordance with the principles presented herein includes relatively fewer parts than similar known transceiver designs, which yields a simpler, more stable and lower cost system. This in turn increases the potential for high volume production of such a transceiver. Further, the present transceiver does not suffer from the limitations described herein that are typically associated with known printed circuit boards. Transceiver design freedom is also greatly enhanced as a result of practice of the above embodiments. 
         [0000]    2. Structural and Operational Aspects of Optical Subassembly Attachment with a Molded Communications Module 
         [0055]    With continuing reference to  FIG. 2 , reference is now made to  FIGS. 4 and 5  in describing various features regarding embodiments of the present invention. 
         [0056]    As briefly described above, suitable electrical connections between optical subassemblies and other portions of the transceiver, such as a printed circuit board, are often difficult to achieve without the use of an intermediary interface, i.e., a flexible circuit or lead frame connector. However, these components add to the complexity of the device and often introduce difficulties in matching impedance along the signal transmission path through the transceiver. 
         [0057]    In accordance with embodiments of the present invention, operable connection of the TOSA  118  and ROSA  120  is achieved in a simple manner without the use of interposed structures, such as flexible circuits, lead frame connectors, and the like. In particular, and as has been mentioned, the TOSA interconnect portion (“TIP”)  122  and ROSA interconnect portion (“RIP”)  124  of the transceiver  100  are configured as part of a system to enable operable interconnection between the transceiver body  110  and the TOSA  118  and ROSA  120 , respectively. As mentioned, the system described herein is configured for use with a four Gigabit SFP optical transceiver module; however, transceivers and other molded communications modules made in accordance with the principles taught herein can also benefit from the present disclosure. 
         [0058]    In greater detail, TIP  122  and RIP  124  each include a plurality of wall holes  122 A and  124 A, respectively, which are defined through a front end wall  112 A, best seen in  FIG. 5 . The inner cylindrical surfaces of the wall holes  122 A and  124 A are conductively plated and are in physical and electrical communication with corresponding lead seats  112 B and  124 B, respectively, defined on the top body surface  110 A adjacent an interior portion of the front end wall  112 A, best seen in  FIGS. 1A and 1B . Note that the wall holes  122 A and  124 A of the TIP  122  and RIP  124  are arranged such that some of the lead seats  122 B and  124 B are disposed on the top body surface  110 A and some on the bottom body surface  110 B, as best seen in  FIG. 1A and 1B . 
         [0059]    Each of the lead seats  122 B,  124 B is electrically connected with a corresponding one of front end top traces  134 E or front end bottom traces  134 F. The traces  134 E,  134 F are produced as a result of the laser direct structuring process described above, and are configured to electrically connect with other components or features of the transceiver  100 , host device, or other structure. Note that in the present embodiment, pairs of the front end top traces  134 E are positioned on opposite vertical sides of third and fourth ridges  160 C or  160 D, which in turn are defined on the top transceiver body surface  110 A. The structure and operation, including broadside coupling, of the ridges  160 C/ 160 D and traces  134 E are similar to that described in connection with the first and second ridges  160 A/ 160 B and the data signal trace pairs  134 A/ 134 B. 
         [0060]    In addition, the lead seats  122 B,  124 B are configured to receive a corresponding one of the leads  126 ,  128  of the TOSA  118  or ROSA  120 , respectively, so as to establish electrical communication between traces and components of the transceiver body  110  and the TOSA/ROSA. In particular, and as best seen in  FIGS. 1A and 1B , each lead seat  122 B/ 124 B defines a half cylindrical concavity extending parallel to the horizontal surfaces of the transceiver body  110 . Also, the lead seats  122 B/ 124 B are positioned with respect to one another so as to enable each seat to receive a corresponding one of the four leads  126  (TOSA) or five leads  128  (ROSA). This is achieved by configuring the thickness of transceiver body  110  to allow the wall holes  122 A/ 124 A and lead seats  122 B/ 124 B to be positioned proximate the top and bottom transceiver body surfaces  110 A/ 110 B.  FIG. 6  shows that the middle lead  128  of the ROSA  120  is raised further above the other two leads shown so as to accommodate this lead. Note that the positioning of the leads of the TOSA  118  and ROSA  120  as they extend from the respective TOSA or ROSA bodies are typically fixed in accordance with industry standards. In this configuration, ready interconnection between the lead seats  122 B/ 124 B and the corresponding traces  134 E/ 134 F is achieved. 
         [0061]      FIGS. 2 ,  6 , and  7  show the transceiver body  110  operably connected with the TOSA  118  and ROSA  120  such that electrical signals can pass there between. In particular, the TOSA leads  126  are received into the wall holes  122 A of the TIP  122  such that the leads are received into the corresponding lead seats  122 B. Similarly, the ROSA leads  128  are received into the wall holes  124 A of the RIP  124  such that the leads are received into the corresponding lead seats  124 B. Once received into the corresponding wall hole  122 A/ 124 A and lead seat  122 B/ 124 B, each lead of the TOSA  118  and ROSA  120  is secured by soldering or other suitable adhesive such that electrical signals can pass to and from the leads and lead seats. 
         [0062]    One advantage realized by the lead interconnection scheme described above is the obviation of the need to bend or otherwise orient the leads of the TOSA  118  or ROSA  120 . This is so by virtue of the ability of the TOSA and ROSA interconnection portions  122  and  124  to provide structure for directly receiving the TOSA/ROSA leads  126  and  128  in their original orientations, as shown in  FIG. 4 . As has already been mentioned, prior known devices have been largely unable to electrically connect with an optical subassembly without either bending the leads or through the use of an intervening structure, such as a flexible circuit or lead frame connector. Lead bending is undesired for its propensity to cause hidden damage to glass seals disposed around the base of each TOSA/ROSA lead when bent to connect with a standard printed circuit board. And, as previously mentioned, the use of intervening structures presents issues with both device complexity and signal path impedance matching. The present invention overcomes the limitations of each of these scenarios by eliminating the need both for intervening structures and bending of the TOSA/ROSA leads, as already described. 
         [0063]    Note that the illustrated interconnection scheme is but one possible configuration for operably connecting an optical subassembly to a molded communications module having plastic circuits. Indeed, it is appreciated that the particular shape and positioning of the elements of the TIP  122 , the RIP  124 , and the TOSA  118 /ROSA  120  can be altered while still benefiting from the functionality of the present invention. For instance, the shape of the TOSA/ROSA leads could be other than cylindrical or could be arranged to extend from the respective OSA base differently from that shown in the accompanying figures. In such cases, the wall holes and lead seats of the TOSA and ROSA interconnect portions could be altered in shape and position to enable operable communication between the OSA and the transceiver or other communications module to be achieved. OSAs having more or fewer leads could also be included, and the number of OSAs connected to the transceiver can vary from what is shown. 
         [0064]    It is also possible to enable the OSA leads to operably connect with the respective wall holes without the use of lead seats. In such a configuration, traces would be defined to operably connect with the wall holes, which holes would be conductively plated. In particular, the OSA leads would be soldered or adhesively attached directly to the wall hole surfaces. This serves as one example of expansion of the principles of the present invention beyond that explicitly illustrated and described herein. 
       3. Structural and Operational Aspects of Trace Interconnection Features 
       [0065]    With continuing reference to  FIG. 3 , reference is now made to  FIGS. 8 and 10 . As briefly described above, various trace interconnection features (“TIF”s)  164  are included as extended portions defined on the transceiver body  110  to enable the temporary interconnection of selected conductive features of the transceiver body. Briefly, the electroless plating process spoken of above deposits a thin layer of conductive material, such as copper or gold, on all surfaces of the transceiver body  110  that have been previously laser etched. However, the thickness of the conductive layer deposited by this process is insufficient to meet the mechanical requirements for certain conductive surfaces of the transceiver body  110 . For instance, the contact pads  130  of the edge connector  116  must include a conductive layer thicker than what can be normally provided via the electroless plating solution. This is necessary partially because of the physical engagement these surfaces undergo when the transceiver  100  is slid into/out of a host device, for example. 
         [0066]    In light of the above limitation with the electroless plating solution, it is necessary to augment the conductive layer thickness of the contact pads  130  to ensure that these surfaces are sufficiently robust for mechanical engagement with the conductive features of the host device. Electroplating is one preferred way by which the contact pad conductive layer thicknesses can be increased. However, in order for electroplating to occur, the surfaces to be plated must be electrically connected one to another. 
         [0067]    The present invention provides a means by which the conductive surfaces to be electroplated can be temporarily and electrically interconnected. Indeed, in one embodiment the TIFs  164  are used to interconnect selected traces  134  of the transceiver body  110 , which traces in turn electrically interconnect the contact pads  130  to be electroplated. 
         [0068]    As best seen in  FIG. 3 , a first set of four TIFs  164 A are included on the transceiver top body surface  110 A proximate the ridges  160 A and  160 B, while a second set of eight TIFs  164 B are included near the outer edges of the transceiver body top surface proximate the trace passaround locations  166 . The TIFs  164 A and  164 B are shaped in the illustrated embodiment as triangular surface features extending from the top body surface  110 A and are conductively coated with a conductive material produced as a result of the laser etching and electroless plating process described further above. In addition, the TIFs  164  are each positioned so as to interconnect adjacent traces to one another. When such TIFs  164 A and B are placed in series adjacent one another, a complete interconnection of all the desired trace  134  occurs. As shown, the TIFs  164  A electrically interconnect the traces or portions of the traces  134 A, B, and C, while the TIFs  164 B electrically connect the traces  134 D that extend to the top body surface  110 A from the bottom body surface  110 B via the trace passaround locations  166 . The two TIFs  164 B nearest the back end  114  of the transceiver body  110  each interconnect with one of the traces  134 D of the top body surface  110 A, thereby completing interconnection of the traces  134 A, B, and C with the traces  134 D. So configured a complete trace interconnection for the desired trace portions is achieved. 
         [0069]    With the desired portions of the traces  134  physically and therefore electrically interconnected as described above, an electroplating process can then be performed as standard in the art to deposit additional conductive material on desired portions of the transceiver body  110  such as, in the present case, the contact pads  130 . Note that additional or alternative conductive features can also be electroplated, thereby illustrating one expansion of the principles of the present embodiment. 
         [0070]    Once the electroplating process is complete, the temporary electrical interconnection of the various traces  134  must be terminated so as to allow for proper discrete operation of each trace once transceiver manufacture is complete. This is achieved by altering each of the TIFs  164  so as to interrupt the electrical interconnection it produces. In one embodiment, this interruption occurs by removing a portion of each TIF  164  by a grinding, milling, cutting, other suitable process. The result of such removal is best seen in  FIG. 5 , wherein a top portion of each triangular TIF  164  has been removed, thereby removing the conductive material on the TIF surface that formerly electrically interconnected the adjacent traces. 
         [0071]    It is not necessary to remove the entire TIF structure, but rather only enough of the TIF structure that is necessary to eliminate any electrical connection between adjacent traces  164 . When removing portions of the TIFs, especially those that will have a portion that remains connected to the high speed data signal traces  134 A and  134 B after removal, care should be taken to remove as much of the TIF as is needed to prevent the unwanted creation of a radiation point by the remaining portion of the TIF. 
         [0072]    Note that  FIG. 8  shows various details regarding the traces  134 D included on the bottom body surface  110 B.  FIG. 8  further shows the manner in which the traces  134 D pass from the bottom body surface  110 B to the top body surface  110 A via the trace passaround locations  166  to interconnect with the TIFs  164 B. Use of the trace passaround locations  166  as configured in  FIGS. 3 ,  8  and  10  enables a convenient transfer of traces from one transceiver body surface to another. 
         [0073]    Note that, though they are disposed in the present embodiment in three general locations on the top body surface  110 A, the TIFs  164 A and B can alternatively be placed and grouped in any number of possible configurations on the transceiver body  110 . For instance, the TIFs could be located in one, two, or more general locations on the transceiver body, both on bottom and top, depending on particular design and structural constraints of the transceiver. 
         [0074]      FIGS. 9A-9C  show cross sectional views of various possible TIF shapes.  FIG. 9A  shows a TIF  364 A having a triangular cross section, similar to the TIFs  164  shown in  FIGS. 3 ,  8  and  10 .  FIG. 9B  shows a TIF  364 B having a semi-circular cross section, while TIF  364 C in  FIG. 9C  has a trapezoidal, mesa-like structure. In addition to these possible shapes, other geometric and non-uniform shapes and configurations are also possible while still preserving the functionality of the TIF. 
         [0075]    Reference is now made to  FIGS. 11A and 11B , which depict details regarding TIFs configured in accordance with another embodiment. In particular, portions of various traces  134  disposed on the top body surface  110 A of the transceiver body  110  are shown in a region proximate the trace passaround location  166 . Between the various traces  134  is a plurality of TIFs  264 , implemented as conductive features defined on the top body surface  110 A by the laser etching and electroless plating described earlier. Indeed, in one embodiment the TIFs  264  are produced integrally with the traces  134  on the top body surface  110 . In the configuration shown in  FIG. 11A , electrical interconnection between the various traces  134  is established via the TIFs  264 . 
         [0076]      FIG. 11B  shows the traces  134  in an electrically disconnected state, wherein the TIFs  264  are no longer interconnecting the traces. In particular, holes  280  are drilled or otherwise defined into the top body surface  110 A to split each TIF  264  and disconnect the traces from one another. A punch, drill, drill press, or other suitable implement can be used to define the holes  280 . The holes  280  need only be defined deep enough into the top body surface  110 A to break the electrical continuity between adjacent traces  134 . However, any suitable hole depth can also be defined, if desired. Also, the shape of the holes can be other than round, if needed.  FIG. 11C  shows a cutaway view of the holes  280 , illustrating the nature of the electrical disconnection of the traces  134  made possible by the holes. 
         [0077]    Though illustrated in  FIGS. 11A and 11B  as located proximate the trace passaround locations  166 , the trace hole configuration shown can alternatively be placed in other locations, such as on the edge connector  116 . These and other possible locations are therefore considered part of the present disclosure. Thus, placement of the TIFs can be chosen so as to minimize interference with other transceiver components. 
         [0078]    Reference is now made to  FIGS. 12A-12C , which depict trace interconnection features employed in a configuration according to yet another embodiment of the present invention. As seen in these figures, a plurality of “punch-out” cavities  480  are interposed between both sets of traces  134  shown. Trace interconnection features (“TIFs”)  464  are also defined between the traces  134  are aligned with the punch-out cavities  480  so as to extend down into and past each punch-out cavity. This arrangement is best seen in  FIG. 12B  where a floor of each punch-out cavity is positioned between either open end of the cavity. This configuration enables the TIFs  464  to electrically connect the traces  134  to one another in preparation for electroplating, as described above. Note that trace interconnection features can be defined on the top, bottom, or both surfaces of the floor of each punch-out cavity. 
         [0079]    After electroplating is complete and interconnection of the traces is no longer needed, the floor of each punch-out cavity  480  is punched out by a suitable punching device. This electrically disconnects the traces  134  from one another, as desired. The design illustrated in these figures has the advantage of maintaining a planar surface in the region of the TIFs without the need for structures rising above the top or bottom surfaces of the transceiver body. 
         [0080]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.