Abstract:
The present invention pertains to a cage for thermal management and housing an electric module comprising a cage housing and having a top, bottom and side walls joined to form an interior cavity and the side walls defining a width of the interior cavity. The top wall may have an air inlet port and an air outlet port and the air inlet and outlet ports spaced apart by a length. The length may be most or all of the width, so that air entering the inlet port will travel over a portion of a side of an electronic module mounted in the cavity prior to exiting the outlet port.

Description:
[0001]    The present invention pertains to a thermal management system for an electronic device housing including a cage having air flow management construction. 
       BACKGROUND 
       [0002]    Thermal management of electronic devices has given rise to many components to deal with heat issues. For example heat sinks are well known for drawing heat away from electronic components such as a microprocessor. Heat sinks make physical contact with a heat developing device. The heat sink may have posts or fins that are elevated to make contact with the air flow above the heat generating device. Air flow removes heat from the posts or rigs. However, such heat sinks do not bring air down to the heat developing device. Also, heat sinks do not make 100% contact with the entire surface of the heat developing device due to imperfections in the flatness of the bottom of the heat sink, imperfections in the flatness of the heat developing device, non-conduction or poor rate of heat transfer due to interfering objects such as recesses or labels. In addition, a heat sink only affects the top surface of the heat developing device upon which the heat sink is mounted. Also, when there are multiple heat developing devices, there in turn need to be multiple heat sinks attached to such devices which may require excessive assembly time and expense. In order to overcome the disadvantages above, applicant has developed the present invention. 
       SUMMARY 
       [0003]    The present invention pertains to a cage for thermal management and housing an electric module comprising a cage housing and having a top, bottom and side walls joined to form an interior cavity and the side walls defining a width of the interior cavity. The top wall may have an air inlet port and an air outlet port and the air inlet and outlet ports spaced apart by a length. The length may be at least 10% of the width, so that air entering the inlet port will travel over a portion of a side of an electronic module mounted in the cavity prior to exiting the outlet port. 
         [0004]    The inlet port may include a canopy protruding beyond the top wall to deflect air flowing across the top wall into the interior cavity of the cage. In an embodiment, the canopy may have an arcuate shape. In an embodiment, the canopy may form a half dome. 
         [0005]    In an embodiment, the inlet port may include an inlet hole and the canopy may enclose a majority of the hole. In an embodiment, the canopy inlet hole is semi-circular in shape and includes a linear side across the diameter of the hole and the canopy enclosing about 180 degrees of the hole on an arcuate side of the hole and providing an opening across the linear side, so that a cross section of canopy forming the opening is a semi-circle. 
         [0006]    In an embodiment, the cage may include multiple cavities for receiving multiple electronic modules on the top wall enclosing multiple cavities and a plurality of inlet and outlet ports formed on the top wall to provide air circulation within the multiple cavities. In an embodiment, the canopy inlet and outlet ports are arranged in a staggered orientation on the top wall so that the adjacent ports do not obstruct the airflow into the adjacent inlet port. In an embodiment, an even number of inlet ports are arranged linearly across the top wall and each inlet port adjacent a first side wall and an odd number of outlet ports are arranged linearly across the top wall and each outlet port adjacent a second side wall. In an embodiment, four inlet ports and three outlet ports are arranged linearly in two rows across the top wall. 
         [0007]    In an embodiment, the outlet port includes a canopy protruding across the top wall and the canopy forming an opening to direct exhaust out of the interior cavity. In an embodiment, the canopy of the inlet port includes an opening facing in a direction opposite the opening provided by the canopy of the outlet port, so that a stream of air flowing in one direction can enter the inlet port and exit the outlet port. In an embodiment, the opening of the canopy inlet port is oriented to intercept a stream of air flowing parallel to the side walls. In an embodiment, the opening of the canopy of the inlet port is oriented to intercept a stream of air flowing perpendicular to the side walls. In an embodiment, the opening of the canopy of the inlet port is oriented to intercept a stream of air flowing oblique to the side walls. 
         [0008]    In an embodiment, the length between the inlet and outlet port is substantially equal to the width, so that air entering the inlet port will travel over a substantial portion of the side of the electronic module mounted in the cavity prior to exiting the outlet port. In an embodiment, the air deflected by the canopy develops turbulence in order to cause air flow in the cavity on at least two sides of an electronic module residing in the cavity. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention is described through a preferred embodiment in the attached drawings in which: 
           [0010]      FIG. 1  depicts a perspective view of the present invention in an embodiment, having a ganged group of cages; 
           [0011]      FIG. 2  depicts a side elevation cut-away view of an embodiment of the present invention depicting a single cage; 
           [0012]      FIG. 3  depicts a side elevation view of the invention of  FIG. 1 ; 
           [0013]      FIG. 4  depicts a plan view of the invention depicted in  FIG. 1 ; and 
           [0014]      FIG. 5  depicts a schematic view of an alternate embodiment of the present invention having a pair of ganged cages. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The present invention provides for thermal management of electronic device housing and particular embodiments of such invention are described with respect to drawing  FIGS. 1-5  as follows: 
         [0016]    In an embodiment, a cage  10  is provided having a ganged construction for receiving an electronic module  20  received in a first interior cavity  21 . The ganged cage  10  also includes a second interior cavity  22 , third interior cavity  23  and fourth interior cavity  24 . Each of the cavities  21 ,  22 ,  23 ,  24  may receive an electronic module  20  in a ganged orientation. In a preferred embodiment the caged housing  10  is stamped of metal and includes a top wall  30 , a bottom wall  32 , side walls  34 ,  36 , back wall  38  and divider walls  41 ,  42  and  43 . The top wall provides a first panel  30  formed of a single metal sheet covering each of the four cavities  21 ,  22 ,  23 ,  24 . The metal planer first panel  30  has at least one stamped air inlet port  50  and air outlet ports  60 . 
         [0017]    In the embodiment depicted in  FIG. 1  a plurality of air inlet ports  50  are aligned in a row A adjacent side wall  36  and a plurality of air outlet ports  60  are aligned in a row B, adjacent a divider/side wall  41 . The walls  36  and  41  define a width W of the cavity  21 . It can be seen that the rows of ports A and B are arranged so that the ports  50 ,  60  (scoops) are as far to the edges of the cavity  21  as possible and adjacent each wall  36 ,  41  as possible. Each port  50 ,  60  is separated by a length  1 . In an embodiment, the length  1  is from 10% to 100% of the width W. The air stream (moving from the left side of  FIG. 1  to the right) enters inlet port  50  and is received within the interior cavity  21 . Due to the large length L and wide spacing between corresponding ports  50 ,  60 , the air stream will travel through the majority of the cavity  21  and exit at outlet port  60 . In this way it may be understood that the greatest amount of cooling of the module  20  mounted within the cavity  21  will be accomplished when the length L is greatest and the greatest volume of air may interact with the module  20 . In other words, when the inlet port  50  is adjacent sidewall  21  and outlet port  60  is adjacent sidewall  41  the air stream S can flow across the majority of the top surface of the module  20 . 
         [0018]    Similarly, for  FIG. 2  where a single cage  10  is shown housing a single module  20  it can be seen that the length L separating inlet port  50  and outlet port  60  is maximized to be close to the width W. In this way, the air stream S may travel across a substantial portion of the top surface of the module  20  in order to cool the module to the greatest degree. 
         [0019]    Returning the  FIG. 1  it can be seen that the Row A of inlet ports  50  is oriented in a staggered orientation with respect Row B of the outlet ports  60 . Likewise turning to  FIG. 3  and  FIG. 4 , the staggered orientation of these inlet and outlet ports is depicted. As shown the inlet port  50  is offset from outlet port  60 . In this way the air flowing over the top of the first panel  30  will have less of an obstruction due to the offset air ports. For example, turning to  FIG. 4 , the air stream S 1  will enter inlet port  50   a  and it will continue as air stream S 2  and will enter inlet port  50   c  which will feed air into the adjacent interior cavity  22 . Since the outlet port  60  is staggered and is not oriented in front of inlet port  50   c , the air steam S 2  can more easily enter the inlet port  50   c  in order to feed more air into the cavity  22 . Thus, it can be seen the air stream S 1  will continue across the top of the first panel  30  and reach the next inlet port  50   e  feeding cavity  23  and continue into inlet port  50   g  in order to enter into cavity  24 . 
         [0020]    As shown in  FIG. 2 , each port  50 ,  60  includes a canopy  71 ,  72 , an inlet hole  73 ,  74  and an opening  75 ,  76 . With respect to inlet port  50 , the air stream S approaches the opening  75  and is deflected and intercepted by the canopy  71 , so that the air stream S flows through inlet hole  73  and is received within the cavity  21 . Part of the air stream runs along the top of the module  20  (mounted within the cavity  21 ) and is exhausted through outlet hole  74 . The air stream S is intercepted and deflected by canopy  72  and exits opening  76 . As is depicted in  FIG. 2 , some the air stream S will be deflected downward into the cavity  21  and circulate around the sides of the module  20 . 
         [0021]    In an embodiment, as depicted in the  FIGS. 1-5 , the canopy  71  is an arcuate shape and forms a half dome. In an embodiment, the canopy  71  encloses a majority of the inlet hole  73 . The canopy  72  encloses a majority of the outlet hole  74 . In an embodiment, the inlet and outlet holes  73 ,  74  are semi-circular in shape and include a linear side  79  ( FIG. 1 ). The canopy  72  enclosing about 180 degrees of the hole on an arcuate side of the hole  74 . There is an opening  76  across the linear side  79 , so that a cross section of the canopy  72  forming the opening  76  is a semi-circle. In a preferred embodiment, the canopy  72  is stamped out of the metal planner first panel  30  in order to form an air deflector  71 ,  72  to intercept air traveling along the top of the cage  30 . As shown in  FIGS. 1 and 4  a plurality of inlet and outlet ports  50 ,  60  have canopies  71 ,  72  integrally formed with the first panel  30  of the cage  10 . Such stamping provides for an easily manufactured housing that provides for substantial air flow within the cavities  21 ,  22 ,  23 ,  24 . 
         [0022]    In the ganged construction shown in  FIG. 1  and  FIG. 4  there are an even number of inlet ports  50  arranged linearly in a Row A across the top wall and an odd number of outlet port  60  arranged linearly in Row B across the top wall  30 . As shown there are depicted four inlet ports  50  in Row A and three outlet ports  60  in Row B. However, it may be understood that the size or shape of ports  50 ,  60  may be altered so that there are more or less of the outlet ports in each row A, B. In an embodiment, the inlet port  50  includes an opening  75  (shown in  FIG. 2 ) that is facing in a direction opposite the opening  76  provided by the outlet port  60  so that air flowing in air stream as flowing in the direction from left to right across  FIG. 2  can enter the inlet port  50  and exit the outlet port  60 , without changing direction. It may be understood that an air stream S flowing in the opposite direction (as shown in  FIG. 2 ) may also be accommodated by the ports depicted therein. In such an instance, the port  60  would be designated the inlet port and port  50  would be designated the outlet port. 
         [0023]    In an alternate embodiment the inlet and outlet ports  50 ,  60  may be arranged so that an air stream S that is flowing parallel to the side walls  21 ,  34  is intercepted by the opening  75  of the inlet port  50 . In other words, the inlet and outlet ports  50 ,  60  will be rotated 90 degrees from that which is shown in  FIG. 1 , where the air stream travels perpendicular to the side walls  21 ,  34 . In a further alternate embodiment the inlet and outlet ports  50 ,  60  will be oriented to intercept a stream of air that is flowing oblique to the side walls  21 ,  34 . 
         [0024]    As depicted in  FIG. 5 , cage  10  is depicted having a pair of cavities  21 ,  22  for receiving a pair of transceiver modules. However, the cage  10  will be constructed as discussed above having an inlet port  50  and an outlet port  60  operating for each cavity  21 ,  22 . Thus, it may be understood that the present invention provides for thermal management of a cage for receiving an electronic module when the cage has a single cavity therein or any number of cavities. In an alternate embodiment, a single large inlet port  50  and outlet port  60  may be provided for a single interior cavity in order to allow for air flow into and out of the cavity  21 . In this way it may be understood that the module mounted therein may be cooled in an efficient manner. The inlet and outlet ports  50 ,  60  or air scoops act in a directional manner to grab air and direct it into the cavity so that air may flow in one direction over the transceiver module mounted within the cavity. In this way a stream of cold air enters the inlet port  50  and hot air is exhausted separately out of the outlet port  60 . In an embodiment, the inlet and outlet ports  50 ,  60  are formed as part of the housing  10  and no extra components are required. 
         [0025]    Those of skill in the appropriate art will understand that a number of alternative embodiments of the present invention exist. The above description only provides particular embodiments and one in the skill of the art will understand that additional means of implementing the present invention understands that there are additional means of implementing the present invention.