Abstract:
A ganged shielding cage with improved heat transfer capabilities is disclosed. The cage has a plurality of module-receiving openings, or bays arranged in serial, widthwise order. Each such opening is separated from an adjacent opening by an intervening wall that defines, at least partially, a continuous passage, extending lengthwise and communicating with the front and rear portions of the cage. This passage permits air flow to occur between adjacent openings of the cages and between adjacent modules held thereby.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The Present Disclosure claims priority to U.S. Provisional Patent Application No. 61/839,412, entitled “Ganged Shielding Cage With Thermal Passages,” and filed 26 Jun. 2013 with the United States Patent And Trademark Office. The content of this Application is incorporated in its entirety herein. 
         [0002]    The Present Disclosure also claims the benefit of U.S. Provisional Patent Application No. 61/839,414 (Molex Docket No. B2-023 US PRO), entitled “Thermal Interposer Suitable For Electronic Modules,” filed on the same day as the priority claim listed above, the content of which is hereby incorporated herein. 
         [0003]    Finally, the Present Disclosure also claims the benefit of Co-Pending Patent Cooperation Treaty Patent Application No. ______ (Molex Docket No. B2-023 WO), entitled “Thermal Interposer Suitable For Electronic Modules,” filed on the same day as the Present Disclosure, the content of which is hereby incorporated herein. 
     
    
     BACKGROUND OF THE PRESENT DISCLOSURE 
       [0004]    The Present Disclosure relates, generally, to shielding cages utilized with electronic modules, and, more particularly, to cages with improved heat transfer capabilities. 
         [0005]    Electronic modules are typically used to interconnect various electronic devices, such as servers and routers and the like. The modules are part of a cable assembly that utilizes multi-conductor wires terminated to modules at each end of the cable. The modules typically contain circuit boards to which the conductors of the cables are terminated, and these circuit boards have contact pads arranged on them in a pattern to mate with an opposing mating, receptacle connector. These receptacle connectors are mounted to a circuit board and are enclosed by a conductive, usually metal cage that defines a hollow passage, or bay, into which a module is inserted to complete a connection between the cable wires and the circuits on the circuit board. 
         [0006]    In order to maintain high density of electrical circuits, the electronic devices in which modules are used typically utilize multiple port, or bay, shielding cages, commonly referred to in the art as “ganged” cages. These ganged cages can be in a single row format, with multiple ports arranged in only one row, extending in the widthwise direction. Alternatively, they may be in a multiple row format, each row containing an equal number of ports. Heat generated during the operation of these modules presents a problem in that ways must be used to dissipate the heat. In ganged shielding cages, single-thickness sheet metal dividers are used as interior walls of the cage and the modules abut these walls on both sides thereof. Ganged cages have been known to use heat sinks attached to either the top surfaces of the cages themselves, or extend through openings in the cage top surfaces into contact with the top surfaces of the modules. 
         [0007]    In any event, it is desired to improve the thermal transfer capabilities of ganged cages, without excessively increasing their dimensions, so that a desired electrical circuit density is achieved in the devices in which the cages and modules are used. It is also desired that any improved shielding cage have one or more heat transfer paths extending perpendicular to the contact surfaces of any heat sinks utilized in conjunction with the cages. 
         [0008]    The Present Disclosure is therefore directed to an improved shielding cage with thermal transfer capabilities particularly suitable for ganged cage applications, and which provides at least one additional heat transfer path in addition to any heat transfer path defined by a heat sink associated therewith. 
       SUMMARY OF THE PRESENT DISCLOSURE 
       [0009]    Accordingly, there is provided a ganged shielding cage suitable for high speed data transfer applications which has beneficial and improved heat transfer capabilities. 
         [0010]    In accordance with a first embodiment, a ganged shielding cage assembly may be provided in a die-cast, or other one-piece format. The cage has a plurality of openings defined therein, each opening extending lengthwise between opposing front and rear ends of the assembly. Furthermore, the openings are arranged side-by-side, or adjacent order. In this regard, the individual openings are separated from each other by an intervening wall member. In instances where the cage assembly is die-cast, the wall member is a hollow, elongated member containing a lengthwise passage extending between front and back ends, which communicates with the exterior of the assembly. This passage provides a means for a coolant to flow though the assembly in a location between modules. The dimensions of the cage openings are such that the sides of the modules contact the wall members so heat may be transferred via the contact. 
         [0011]    In another embodiment, the wall member may be formed from a sheet metal blank folded over itself to define a hollow space between adjacent sides thereof. The blank may include spacer members in the form of tabs that are stamped in them and bent toward each other to define the spacing desired for the air channel. In 1×4 ganged cage arrangements, three of the ports may be separated by the aforementioned air channels and the last port may be speared from adjacent ports by a single sheet metal wall. In such an arrangement, the benefits of increased cooling are obtained and a reduced pitch between cages is possible. 
         [0012]    In yet another embodiment, a press tit thermal interposer may be provided with side supports that serve to not only space the thermal interposer vertically, but also serve to define a separation between adjacent ports. 
         [0013]    These and other objects, features and advantages of the Present Disclosure will be clearly understood through a consideration of the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0014]    The organization and manner of the structure and operation of the Present Disclosure, together with further objects and advantages thereof, may best be understood by reference to the following Detailed Description, taken in connection with the accompanying Figures, wherein like reference numerals identify like elements, and in which: 
           [0015]      FIG. 1  is a perspective view of a shielding cage assembly of known construction with a heat sink member attached to the top portion thereof; 
           [0016]      FIG. 2  is a front elevational view of the shielding cage assembly of  FIG. 1 ; 
           [0017]      FIG. 3  is a front elevational view perspective view of a shielding cage assembly constructed in accordance with the principles of the Present Disclosure; 
           [0018]      FIG. 4  is a rear elevational view of the shielding cage assembly of  FIG. 3 ; 
           [0019]      FIG. 5  is a the same as  FIG. 3 , but with the heat sink member oriented so that the heat dissipating fins thereof are longitudinally disposed on the shielding cage body, or parallel to the module-receiving openings of the cage body; 
           [0020]      FIG. 6  is a perspective view of a intervening wall member formed from a piece of sheet metal to define an interior passage in the wall member; 
           [0021]      FIG. 7  is a sectional view of the shielding cage assembly of  FIG. 3 , looking down into the interior of the cage body; 
           [0022]      FIG. 7A  is an enlarged detail view of the opening of the intervening wall member that defines a heat transfer passage in the form of a slot; 
           [0023]      FIG. 7B  is an enlarged detail view of the opening of the intervening wall member that defines a heat transfer passage that has a plurality of openings communicating therewith; 
           [0024]      FIG. 8  is a perspective view of a thermal interposer with support legs structured to fit into a cage body opening and form a pair of passages alongside any module inserted therein; and 
           [0025]      FIG. 9  is an enlarged detail view of a portion of the front end of the thermal interposer of  FIG. 8 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    While the Present Disclosure may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the Present Disclosure is to be considered an exemplification of the principles of the Present Disclosure, and is not intended to limit the Present Disclosure to that as illustrated. 
         [0027]    As such, references to a feature or aspect are intended to describe a feature or aspect of an example of the Present Disclosure, not to imply that every embodiment thereof must have the described feature or aspect. Furthermore, it should be noted that the description illustrates a number of features. While certain features have been combined together to illustrate potential system designs, those features may also be used in other combinations not expressly disclosed. Thus, the depicted combinations are not intended to be limiting, unless otherwise noted, 
         [0028]    In the embodiments illustrated in the Figures, representations of directions such as up, down, left, right, front and rear, used for explaining the structure and movement of the various elements of the Present Disclosure, are not absolute, but relative. These representations are appropriate when the elements are in the position shown in the Figures. If the description of the position of the elements changes, however, these representations are to be changed accordingly. 
         [0029]      FIG. 1  illustrates a conventional shielding cage assembly  20  that has a die cast cage body, or housing  21 , a sheet metal base  22 , an external heat sink member  23  on its top and a plurality of interior watts  24  that divide the cage into a plurality of module-receiving bays, or passages  25 . The interior walls  24  are formed from sheet metal blanks and are inserted into the cage assembly  20 . A gasket  26  is provided that encircles the front of the cage assembly  20  and which provides EMI protection when the cage is mounted to a circuit board  30  and a bezel, or cover plate (not shown) is attached to the cage assembly  20 . 
         [0030]    As illustrated in  FIG. 2 , the cage assembly  20  includes solid interior walls  24  which, as noted above, may be formed as inserts from sheet metal, or they may be an integral part of the cage body  21 when it is of die cast construction. Sheet metal gaskets  31  with a plurality of spring fingers  32  are provided and are attached to the top and bottom  33 ,  34  edges of each such cage bay. Similar gaskets  35 ,  36  are also provided that engage the interior walls and side walls, respectively, so that the spring fingers  32  attached thereto project into the interior of the cage bays  25  so as to make contact with the housing of any module inserted therein. 
         [0031]      FIG. 3  is a front elevational view of a shielding cage assembly  40  constructed in accordance with the principles of the Present Disclosure. The cage assembly  40  includes a die-cast cage body  41  that has a defined bottom and rear wall  42  and  43 , side walls  44  and interior walls  45 . The interior walls  45  separate the cage into a plurality of lengthwise module-receiving bays  46 . In one important aspect, the interior walls  45  of the cage assembly are provided with a thickness sufficiently large that they can accommodate (or define) a heat transfer passage  47  that extends longitudinally therein from the front end  48  of the cage body to the rear end  49  thereof. These passages  47  communicate with the exterior of the cage. The heat transfer passages  47  thereby define a series of fluid channels that are interposed between the module-receiving bays  46  and the modules inserted therein. The fluid channels convey an appropriate cooling fluid, such as air, water or oil, depending on the cooling system utilized, through the cage assembly form front to back to provide additional cooling. 
         [0032]    A heat sink member  50  is attached to the top of the cage body and the heat sink member  50  has a heat transfer surface on its bottom that either contacts the tops of any module inserted into any of the module-receiving bays  46 . The heat sink member  50  may include a plurality of vertical heat-dissipating fins  52  that may be oriented either perpendicular to the bays  46  as illustrated in  FIG. 3 , or parallel as illustrated in  FIG. 8 . Heat is transferred from the modules to the heat sink member  50  by way of the contact that occurs between the two elements. Similarly, the modules of the system are inserted into their respective bays  46  so that the sides of the modules contact the opposing surfaces of the interior walls  45  of the cage assembly. Air, or another selected cooling fluid, is passed through the heat transfer passages  47  at a temperature lower than the operating temperature of the modules. The contact of the cooling fluid with the walls that define the heat transfer passages  47 , or the modules themselves will convey the heat into the heat transfer passages  47  and out of the cage assembly. 
         [0033]    As illustrated in  FIGS. 7, 7A and 7B , the openings of the heat transfer passages  47  may take the form of slots  54 , which is particularly suitable for use in die-cast cage structures, or as illustrated in  FIG. 79 , they may take the form of circular bores, or holes  55 . Preferably, holes  55  are located on the front, or outward, face of the cage, while slots  54  may be located on the rear face between each port, or may be on the front of the cage. In any event, the size of the openings should be sufficiently large to permit reliable cooling air flow, whether the system is under pressurized cooling, or not.  FIG. 6  illustrates another embodiment of an interior wall member  60  for use with cooling systems of the Present Disclosure. This interior wall member  60  in this embodiment is formed out of a sheet metal blank  61  and is shown as bent over upon itself to define a spacing, or heat transfer passage  62  disposed between two sides  64 ,  65  of the interior wall member  60 . With such a structure, the module to module spacing of the cage assembly may be reduced as compared with a die-cast cage structure. One or more ends of such the interior wall member  60  may have an end cap or the like with the cooling openings, such as the slots  54  or bores  55  depicted in  FIGS. 7A-B , disposed therein. 
         [0034]      FIGS. 8-9  illustrate another embodiment of an insert member  70  used to define the cooling passages. Such a member is a thermal interposer  72 , the details of which are disclosed in more detail in the Co-Pending U.S. Provisional Patent Application, indicated in Paragraph 0001, above. The interposer  72  has a base, or body portion  71  with a series of upraised lugs  73  that engage slots in the heat sink member  50  which is applied to the top of the cage assembly, and a series of downwardly depending contact arms  74  that extend into the module bay and make contact with the top surface of the module inserted therein. It should be noted that the path formed by contact aims  74 , body portion  71  and tugs  73  conducts heat to the heat sink. The interposer  72  is provided with a pair of leg members  75  (preferably spaced away from the module and which are bent from the interposer base in an inverted U-shape  77  to define additional potential cooling passages  76  that run lengthwise proximate to the intersection of the interposer base  71  and each leg member  75 . The leg members  75  may further include a bent portion  78  disposed in a portion thereof that extends in an offset manner from the longitudinal extent of the leg members In this manner, a spacing is created between the sides of a module inserted into the bay (or the interposer leg members) and the interior walls of the cage assembly. Openings are preferably formed as part of the bent portion to facilitate sufficient fluid passage through the spacing. 
         [0035]    While a preferred embodiment of the Present Disclosure is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing Description and the appended Claims.