Patent Document

BACKGROUND 
       [0001]    This application relates to cooling passages that will deliver and then return cooling fluid for an electronic component. 
         [0002]    Electronics are becoming utilized in more and more applications. The size of electronic components is continuously being reduced. There are now any number of electronic chips that are on the order of one millimeter by one millimeter, or even smaller. 
         [0003]    As the applications controlled and performed by the electronic components have increased, the heat generated by the electronic components has also increased. The historic ways of dissipating heat, such as heat fins, may no longer always be adequate. 
         [0004]    Thus, it becomes important to provide cooling fluid in an efficient manner to the very small electronic components. 
         [0005]    However, given the extremely small sizes involved, the formation of the required passages to supply cooling fluid is challenging. Further, supplying fluid, and then returning fluid in an efficient manner, and with control over the pressure losses, and other flow characteristics, has proven challenging. 
       SUMMARY 
       [0006]    A cooling supply package for an electronic component has a supply port communicating with a plurality of outer supply channels, and a return port communicating with a plurality of outer return channels. The outer supply channels and outer return channels communicate with distinct ones of openings in a slot layer and into return and supply slots, respectively. An orifice layer supplies fluid to an electronic component to be cooled from supply slots and receives return fluid into the return slots after having cooled the electronic component. A cooling supply and electronic component combination is also disclosed. 
         [0007]    These and other features may be best understood from the following drawings and specification. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  shows an electronic component. 
           [0009]      FIG. 2  shows a cooling supply and electronic component combination. 
           [0010]      FIG. 3  shows further details of the combination. 
           [0011]      FIG. 4  shows a first layer in a cooling package. 
           [0012]      FIG. 5  shows a subsequent layer. 
           [0013]      FIG. 6  shows another subsequent layer. 
           [0014]      FIG. 7  shows further layers. 
           [0015]      FIG. 8  shows a detail of the  FIG. 7  layer. 
           [0016]      FIG. 9A  shows the shape of the actual flow passages for delivering cooling fluid. 
           [0017]      FIG. 9B  shows a detail of  FIG. 9A . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIG. 1  shows a electronic assembly  20  that includes an electronic component  22 , such as a silicon chip or any other electronic component. Such components may be on the order of one millimeter by one millimeter, or even smaller. However, no size limitation should be taken as being implied by this example. Component  22  is shown communicating, as known, with a schematically shown system  19  through pins  28 . 
         [0019]    Electronic component  22  is the electronic portion itself. Electronic component  22  has a zone  24  and a zone  26  that may generate more heat than zone  24 , in one example. 
         [0020]      FIG. 2  shows a cooling fluid assembly or package  30  for the electronic component  22 . 
         [0021]    The package  30  incorporates a supply port  17 , a supply plenum  42 , a return port  19  and a return plenum  40 . As shown, the electronic component  22  is in contact with an impingement channel layer  32 . An orifice layer  34  is spaced further away from the assembly  20 , and a slot layer  37  is spaced outwardly of the orifice layer  34 . Headers  36  and  38  each serve one of the plenums  40  and  42 . 
         [0022]    In embodiments, as mentioned, the electronic component  22 , which is part of the assembly  20  may be on the order of one millimeter by one millimeter. The total package  30  for such a component may extend for a left to right hand distance (as shown in  FIG. 2 ) on the order of two millimeters. A thickness measured perpendicular to a face of the assembly  20  of the impingement channel layer  32  may be 0.1 millimeter, a thickness of the orifice layer  34  may be 0.015 millimeter, a thickness of the slot layer  37  may be 0.035 millimeter, a thickness of the header layer  36  may be 0.065 millimeter, and a thickness of the header layer  38  may be 0.070 millimeter. In general, the layers have thicknesses that are all preferably less than 0.15 millimeter, and the thicknesses of the orifice layer  34  and slot layer  37  are less than 0.05 millimeter. 
         [0023]    As can be appreciated, the several layers  32 ,  34 ,  37 ,  36 , and  38  provide a very compact overall package  30 . As will be explained below, the layers deliver fluid to cool the electronic component  22  in an efficient and reliable manner. 
         [0024]      FIG. 3  shows the package  30 , with the supply tube  17  communicating with a supply channel  46 . A source of cooling fluid  45  communicates into the channel  46 . Similarly, the return tube  19  communicates with a channel  44  that delivers the fluid back to a downstream destination  47 , which may communicate with a heat exchanger HE. 
         [0025]    That is, the cooling fluid may pass through a closed circuit between the downstream destination  47  and supply  45 , with an intermediate heat exchanger HE. A size of the channels  44  and  46  may be on the order of 0.15 millimeter by 1.0 millimeter. 
         [0026]      FIG. 4  shows the impingement channel layer  32 . The impingement channel layer has a zone  131  with channels  132 . A zone  136  has channels  134 . The density of channels  134  in zone  136  is higher than the density of channels  132  in zone  131 . In general, the spacing between channels  134  is less than the spacing between channels  132 . 
         [0027]    As can be appreciated, the zone  136  corresponds to the higher heat generating area  26  while the zone  131  is positioned over the lower heat generating area  24 . The channels  132  and  134  are shown to extend generally along an entire length of the electronic component  22 . The channels  132  and  134  may have a width of approximately 0.0060 millimeter, and a height of 0.050 millimeter. More generally, the width of the channels  132  and  134  is less than 0.010 millimeter. 
         [0028]      FIG. 5  shows an orifice layer  34 . An area  140  has holes or orifices  142 , while an area  144  has holes or orifices  146 . As can be appreciated from  FIG. 5 , the density of holes  146  in area  144  is much greater than the density of holes  142  in area  140 . Again, this corresponds to the zones  24  and  26  on the electronic component  22 . The orifices  142  and  146  may have a hydraulic diameter of 0.0055 millimeter. In general, the hydraulic diameter of the orifices is less than or equal to 0.10 millimeter. 
         [0029]    A top, or outer face, of a slot layer  37  is illustrated in  FIG. 6 . The slot layer  37  has a plurality of slots  156  in an area  152  and a plurality of slots  154  in an area  150 . The density of slots  154  in area  150  is greater than the density of slots  156  in area  152 . Again, the area  150  corresponds to the high heat zone area  26  on the chip  22 . 
         [0030]    As shown in  FIG. 6 , within area  152 , there are actually wider slots  156 W, and shorter slots  156 S. The slots  156 S are typically aligned with flow that would include the higher density slots  154 . Thus, the volume of fluid supplied to cool or be returned from the higher heat generating area on the electronic component  22 , results in a smaller volume through the smaller slots  156 S. 
         [0031]      FIG. 7  shows further details of the slot layer  37 . The channels in layer  32  and orifices in layer  34  are omitted here. Channels  190  extend between ribs  191 . Similarly, channels  192  extend between ribs  193 . The effect of the ribs  191 ,  193  is to break the flow between the orifice layer  34  and the slot layer  37  into separate flows. One set of channels  190  communicates with columns  200  in a supply header  36  while an adjacent channel  190  communicates through slots  156  to an area  210  between columns  200 . As can be seen, columns  200  and area  210  are formed within a return header  36 . 
         [0032]    As can be appreciated from  FIG. 7 , columns  301  associated with the higher density range extend along an entire length of the higher density range. Spaced into the plane of this paper would be a similar elongated portion of an upper supply header  38 . 
         [0033]    Channels  212  between the columns  200  communicate with an area  214  and then the return port  19 . Area  214  is the interior of the plenum  40 . 
         [0034]    A wall  310  of the supply header  38  blocks flow from its spaces  202  and its channels  205  from reaching area  214 . 
         [0035]    Similarly, a wall  330  on the return header  36  blocks flow from the areas  210  and channels  212  from reaching an area  204  and communicating with the supply port  17 . Area  204  is the interior of plenum  42 . 
         [0036]      FIG. 8  shows detail of a top surface of the return header  36 . There are openings or slots  220  over the columns  200  in a low density area  222 . There are closed areas over the channels  212  between the columns  200 . As shown, there is a higher density of slots or openings  224  over the central area  226 , which will in turn relate back to all of the other high density areas, and eventually back to the high heat flux area  26 . 
         [0037]    Here again, there are wider slots  220 W, and wider columns  200 W, and shorter or smaller slots  220 S and smaller columns  200 S, again associated with area  222 . The smaller slots and columns  220 S and  200 S will be in flow communication with the area  226 , which will receive a higher percentage of the flow. Use of the columns  200  evenly distributes fluid across the entire surface of the orifice plate and at a uniform pressure. The columns  200  also provide structural support, so that the layers of silicon are not separated due to the pressure being distributed across an entire unsupported area. 
         [0038]      FIG. 9A  is a reverse model of the layers  36 ,  37  and  38 .  FIG. 9A  is actually illustrating the flow passages and not the structure. As can be appreciated, there are channels  190  and  192 , which are found in the slot layer  37 . Further, the supply channel spaces  180  can be seen communicating with the area  204 , and then the supply port  17 . The return port  19  communicates with the area  214  and the channels  212 . Passages  174  are formed within the columns  200 . Passages  181  are formed between the columns  400  in the upper header  30 . 
         [0039]      FIG. 9B  is also a reverse model of the layers  34 ,  37  and  36 . The holes or orifices form flow spaces  172 . As shown, these are separated by a break  300  from other holes or spaces  176 , to provide return and supply holes. Further, there are spaces  172 H at the higher density area, and spaces  172 L at the lower density area. The slot layer  37  provides slots  170 H and  170 L, respectively. Structure  182  corresponds to the columns, and spaces  180  correspond to the channels  210  in the layer  36 . 
         [0040]    Since  FIGS. 9A and 9B  are “reverse” of the structural  FIGS. 1-8 , it should be understood that breaks, such as shown at  300 , between a channel  170  and the space  180  would actually be defined by structure. That is, there is a wall separating those flow passages in the actual package  30 . 
         [0041]    In embodiments, the total flow area of the return flow area  214  is greater than the total flow area of the supply flow area  204 . In embodiments, the return header flow area was 0.60 millimeter 2  while the total flow area of the supply header was 0.35 millimeter 2 . In embodiments, the total flow area of the return header is at least 1.5 the total flow area of the supply header. 
         [0042]    It should be understood that the sizes disclosed throughout this application are to be seen as exemplary, and illustrate the extremely small size of the package which is provided to cool the electronics assembly  20 . As can be appreciated, all of the flow passages and the structure disclosed to form the flow passages are extremely small. The structure may be layered utilizing known silicone etching techniques or other layering techniques appropriate for such small construction. 
         [0043]    The complete supply of fluid to the surface of the electronic component  22  and the return will now be described. Fluid is supplied into channel  46  and through supply port  17  into the area  204 . This fluid flows into channels  212  and through slots  154 / 156  on top of the slot layer  37 . The slots  154 / 156  lead into channels  190 / 192  in the slot layer  37 , then through orifices or holes  146  or  142  in the orifice layer  34 , and into channels  132  or  134  in the impingement channel layer  32 . 
         [0044]    The fluid is then directed off surfaces on the electronic component  22 . Since the holes or orifices  146  and  142  are small, the fluid impinges in a jet flow. The fluid flows along the channels  132  or  134  and then passes back through other holes  142  or  146  in the orifice layer  34  at locations aligned with slots  156  or  154  in the slot layer  37  that connect into columns  200 . 
         [0045]    This will, in turn, supply the fluid into channels  205  to pass into the area or plenum  214  and then the return port  19 . From return port  19 , the fluid returns to the channel  44  and the downstream location  47 . 
         [0046]    The present invention thus provides a way of providing uniform pressure fluid and a variation in the volume of fluid supplied to distinct areas on an electronic component. 
         [0047]    In one embodiment, the cooling fluid utilized may be a Freon-based refrigerant such as FC3283. Of course, other fluids including liquid and gaseous fluids, may be utilized. 
         [0048]    Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the true scope and content of this disclosure.

Technology Category: h