Abstract:
An apparatus includes a microchannel structure that has microchannels formed therein. The microchannels are for transporting a coolant and are intended to be proximate to an integrated circuit to transfer heat from the integrated circuit to the coolant. The apparatus further includes a cover positioned on the microchannel structure. The cover has formed therein a right-angle passage to provide fluid communication between a first port on a lower horizontal surface of the cover and a second port on a vertical surface of the cover. The cover includes a plurality of tabs. Each tab extends from a respective corner of the cover. The tabs each have an aperture formed therein. The apertures are shaped and sized to receive a fastener.

Description:
BACKGROUND  
       [0001]     As microprocessors advance in complexity and operating rate, the heat generated in microprocessors during operation increases and the demands on cooling systems for microprocessors also escalate. Cooling systems for microprocessors have been proposed in which a coolant such as water is circulated through narrow channels (known as “microchannels”) which are close to or formed in the microprocessor die. One issue that may be encountered in microchannel cooling systems is potential difficulty in connecting tubes for the coolant path to the cover of a microchannel assembly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0002]      FIG. 1  is a schematic side cross-sectional view of a system.  
         [0003]      FIG. 2  is a schematic side cross-sectional view of another embodiment of a system.  
         [0004]      FIG. 3  is a schematic horizontal cross-sectional view of a microchannel structure that is part of the systems of FIGS.  1  or  2 .  
         [0005]      FIG. 4  is a schematic side cross-sectional view of a manifold plate that is part of the systems of FIGS.  1  or  2 .  
         [0006]      FIG. 5  is an exploded view showing more details of the system of  FIG. 1 .  
         [0007]      FIG. 6  is an isometric view showing the manifold plate of  FIG. 4  in more detail.  
         [0008]      FIG. 7  is an isometric view showing on a larger scale a grommet which also appears in  FIG. 6 .  
         [0009]      FIG. 8  is a view similar to  FIG. 6 , showing the manifold plate with O-rings instead of grommets.  
         [0010]      FIG. 9  is a view similar to  FIGS. 6 and 8 , showing the manifold plate with a gasket instead of grommets or O-rings.  
         [0011]      FIG. 10  is an exploded view showing another embodiment of the manifold plate.  
         [0012]      FIG. 11  is an inverted schematic plan view of still another embodiment of the manifold plate. 
     
    
     DETAILED DESCRIPTION  
       [0013]      FIG. 1  is a schematic side cross-sectional view of a system  100  including an Integrated Circuit (IC)  110 . The IC  110  may be associated with, for example, an INTEL® PENTIUM IV processor. To help remove heat generated by the IC  110 , a liquid coolant (not separately shown) may be circulated through a microchannel cold plate  120 . The microchannel cold plate  120  may be located proximate to the IC  110  to facilitate the removal of heat from the system  100 . The microchannel cold plate  120  may, for example, be thermally coupled to the IC  110  by a thermal interface material (TIM)  130 . (In some cases, the TIM  130  may be omitted and the microchannel cold plate  120  may be directly thermally coupled to the IC  110 . In some cases a rear side of the IC  110  may be thinned to reduce thermal resistance between the IC  110  and the microchannel cold plate  120 , which may be coupled to the rear side of the IC  110 .) Heat may be transferred from the IC  110  to the coolant, which may then leave the system  100 . For example, the coolant may exit from the microchannel cold plate  120  via an outlet tube  140  and may be circulated to a heat exchanger (not shown) and then to a pump (not shown). The heat exchanger may for example include a length of tube with heat-conductive fins (not shown) mounted thereon and a fan (not shown) to direct air through the fins. Heat transferred to the coolant in the microchannel cold plate  120  may be dissipated at the heat exchanger. After passing through the heat exchanger and the pump, the coolant may flow back to the microchannel cold plate  120  via an inlet tube  150 .  
         [0014]     The microchannel cold plate  120  may be formed from a microchannel structure  160 , in which microchannels (not separately shown in  FIG. 1 ) are formed, and a cover lid  170  which is positioned on the microchannel structure  160  and which closes the top of the microchannels. The system  100  also includes a manifold plate  180  which is mounted on the cover lid  170  and functions to facilitate connection of the tubes  140 ,  150  to the microchannel cold plate  120 .  
         [0015]     In some aspects, the cover lid  160  may be considered part of the microchannel structure and the manifold plate  180  may be considered a cover on the microchannel structure.  
         [0016]     The coolant may be water, or a liquid antifreeze compound that has a lower freezing point than water, or an aqueous solution of such a compound.  
         [0017]      FIG. 2  is a view similar to  FIG. 1 , showing another embodiment of the system. In this embodiment, labeled  100   a , the cover lid and the manifold plate shown in  FIG. 1  are integrated into a single member, labeled  180  in  FIG. 2 , and functioning as a cover for the microchannel structure  160 .  
         [0018]      FIG. 3  is a schematic view taken in horizontal cross-section of the microchannel structure  160  according to some embodiments.  FIG. 3  shows parallel microchannels  302  formed in the microchannel structure  160 . (The number of microchannels may be more or fewer than the number illustrated in  FIG. 3 , and the drawing is not necessarily to scale. The microchannels need not be configured as shown in  FIG. 3 . For example, alternative microchannel configurations are shown in co-pending commonly-assigned patent application no. 11/101,061, filed Apr. 7, 2005.)  
         [0019]     Coolant (not shown) flows to the microchannels  302  via an inlet port  304  (shown in phantom and formed in the cover lid or manifold plate, which are not shown in  FIG. 3 ) and an inlet plenum  306 . The coolant flows out of the microchannels  302  via an outlet plenum  308  and an outlet port  310  (shown in phantom and formed in the cover lid or manifold plate).  
         [0020]      FIG. 4  is a schematic side cross-sectional view showing some details of the manifold plate  180 . (Other details of the manifold plate are omitted from  FIG. 4 .) The manifold plate  180  has a lower horizontal surface  402 , a left side vertical surface  404  and a right side vertical surface  406 . (As used herein and in the appended claims, a “vertical surface” should be understood to include any surface that departs substantially from the horizontal; and “horizontal” refers to any direction normal to the direction from the microchannel assembly to the IC.)  
         [0021]     The manifold plate  180  has formed therein an inlet passage  408 . The inlet passage  408  provides fluid communication between a port  410  on the lower horizontal surface  402  of the manifold plate  180  and a port  412  on the left side vertical surface  404 . The inlet passage  408  is a right-angle passage in that it is formed of a vertical course  414  and a horizontal course  416  that joins the vertical course  414  at a right angle. (More generally, as used herein and in the appended claims, “right-angle passage” refers to any passage that supports at least an 85° change in flow direction therethrough.)  
         [0022]     The manifold plate  180  also has formed therein an outlet passage  418 . The outlet passage  418  provides fluid communication between a port  420  on the lower horizontal surface  402  of the manifold plate  180  and a port  422  on the right side vertical surface  406 . The outlet passage  418  is a right-angle passage in that it is formed of a vertical course  424  and a horizontal course  426  that joins the vertical course at a right angle.  
         [0023]      FIG. 5  is an exploded view showing more details of the system  100 .  FIG. 5  shows a circuit board  502  and a socket  504  mounted on the circuit board  502 . The package of the IC  110  is shown installed in the socket  504 . The microchannel cold plate  120  is shown positioned on the IC  100 . Shown spaced above the microchannel cold plate  120  is the manifold plate  180 . As best seen in  FIG. 6  (which is an isometric view of the manifold plate  180  seen from below), the manifold plate  180  has four tabs  602 , each of which extends from a respective corner of the manifold plate  180 . In particular, tabs  602 - 1  and  602 - 2  are aligned with each other and extend in opposite directions from each other, along a common line, from adjacent corners of the manifold plate  180 . In addition tabs  602 - 3  and  602 - 4  are aligned with each other and extend in opposite directions from each other, along a common line, from adjacent corners of the manifold plate  180 . It will be observed that the tabs  602  all share an orientation in that the longitudinal axes of the tabs are all parallel to, or coincident with, each other. All of the tabs  602  lie in a common plane.  
         [0024]     Each of the tabs  602  has a respective aperture  604  formed at an outer end of the tab. Each aperture is shaped and sized to receive a fastener, such as the screws  606  shown installed in the tabs  602  in  FIG. 5 . Continuing to refer to  FIG. 5 , a respective spring  608  and a respective backing washer  610  are installed on each of the screws  606 .  
         [0025]     A pair of grommets  612  are provided to seal the ports  410 ,  420  ( FIG. 4 , not visible in other drawings) on the lower horizontal surface  402  ( FIG. 6 ) of the manifold plate  180  to the ports  304 ,  310  ( FIGS. 5 and 3 ) on the microchannel cold plate  120 , respectively. ( FIG. 7  shows one of the grommets  612  on a larger scale. Each grommet may be formed of a suitable rubber, elastomer or plastic material.)  
         [0026]     The system  100  also includes a backing plate  506  ( FIG. 5 ) which may be secured to the floor (not shown) of a personal computer chassis (not shown) to allow for suitable installation of the system  100 . The backing plate  506  is generally shaped as a planar hollow square with corner extensions that each include a receptacle  508  to receive the tip of a respective one of the screws  606 . By threadedly engaging the screws  606  in the receptacles  508  and tightening the screws  606  against the force of the springs  608 , the manifold plate  180  and the microchannel cold plate  120  may be clamped down onto the circuit board  502  and the IC  110  to assure good thermal coupling of the microchannel cold plate  120  to the IC  110  and positive sealing (via the grommets) of the ports on the bottom of the manifold plate  180  to the ports in the cover lid (not separately indicated in  FIG. 5 ) of the microchannel cold plate  120 .  
         [0027]      FIG. 8  is a view similar to  FIG. 6 , showing that O-rings  802  may be substituted for the grommets  612  that were previously referred to. Similarly,  FIG. 9  shows that a gasket  902  (to be sandwiched between the microchannel cold plate  120  and the manifold plate  180 ) may be employed in place of the grommets or O-rings. All of these arrangements may be advantageous by supporting re-workability, i.e., comparatively convenient disassembly, if required, of the manifold from the microchannel cold plate.  
         [0028]      FIG. 10  is an exploded view showing another embodiment of the manifold plate, now labeled  180   a . As seen from  FIG. 10 , the manifold plate  180  may be composed of a metal base plate  1002  and a molded plastic component  1004 . The base plate  1002  may be generally square and planar, with four tabs  1006  (only 3 visible in the drawing) each extending radially outwardly from a respective corner of the base plate  1002 . An aperture  1008  to receive a respective fastener (not shown) is formed at the end of each of the tabs  1006 . Holes  1010  are formed in the main body  1012  of the base plate  1002 .  
         [0029]     The molded plastic component  1004  has right angle passages  1014  (shown in phantom) formed therein. The component  1004  allows for low cost manufacture of the manifold plate  180   a , while the base plate  1002  may be formed of high strength steel or the like to promote overall strength of the manifold plate  180   a . The molded plastic component  1004  may be secured to the base plate  1002  by a suitable adhesive (not shown). The manifold plate  180   a  shown in  FIG. 10  may be used in place of the manifold plate  180  in the systems  100  ( FIG. 1 ) or  100   a  ( FIG. 2 ).  
         [0030]      FIG. 11  is an inverted schematic plan view of still another embodiment of the manifold plate, now labeled  180   b . The lower horizontal surface  1102  of the manifold plate  180   b  is shown in  FIG. 11 . Indicated at  1104  is a left side vertical surface of the manifold plate  180   b ; a right side vertical surface (facing in the opposite direction from surface  1104 ) of the manifold plate  180   b  is indicated at  1106 . The manifold plate  180   b  also has a near side vertical surface  1105  and a far side vertical surface  1107 . The manifold plate  180   b  has an inlet right-angle passage  1108  and an outlet right-angle passage  1110 . The inlet right-angle passage  1108  provides fluid communication between a port  1112  on the lower horizontal surface  1102  and a port  1114  on the left side vertical surface  1104 ; the outlet right-angle passage  1110  provides fluid communication between a port  1116  on the lower horizontal surface  1102  and a port  1118  on the left side vertical surface  1104 . The inlet right-angle passage  1108  has a horizontal course  1120  (indicated in phantom) that runs from port  1114  in the direction toward port  1112 ; the outlet right-angle passage  1110  has a horizontal course  1122  (indicated in phantom) that runs from port  1118  in the direction toward port  1116 . (It will be appreciated that the outlet right-angle passage  1110  may alternatively be used as an inlet for coolant, with the inlet right-angle passage  1108  serving as an outlet for coolant.)  
         [0031]     As shown in  FIG. 11 , the port  1116  is spaced from the left side vertical surface  1104  by a greater distance than is the port  1112 . In some embodiments, the port  1116  may be spaced from the right side vertical surface  1106  by a distance that is substantially equal to the distance that the port  1112  is spaced from the left side vertical surface  1104 . It will be observed that the horizontal course  1122  of the right-angle passage  1110  is longer than the horizontal course  1120  of the right-angle passage  1108 , and that the two horizontal courses run parallel to each other. Moreover, the shortest distance between port  1112  and left side vertical surface  1104  is less than the shortest distance between port  1116  and left side vertical surface  1104 , and the shortest distance between port  1112  and far side vertical surface  1107  is less than the shortest distance between port  1116  and far side vertical surface  1107 . (As used herein and in the appended claims, a “vertical surface” should be understood to include any surface that departs substantially from the horizontal; and “horizontal” refers to any direction normal to the direction from the microchannel cold plate to the IC.)  
         [0032]     The manifold plate  180   b  shown in  FIG. 11  may be used in place of the manifold plate  180  in the systems  100  ( FIG. 1 ) or  100   a  ( FIG. 2 ). (It is assumed that the ports in the cover lid  170 — FIG. 1 —are positioned to match the staggered positions of the ports  1112 ,  1116  of the manifold plate  180   b .) With the arrangement of ports and right-angle passages shown in  FIG. 11 , inlet and outlet tubes (not shown in  FIG. 11 ) may be attached to the microchannel cold plate from the same direction, while allowing the coolant to flow from one end of the cold plate to the other. This may allow for convenient “plumbing” to the microchannel cold plate.  
         [0033]     The several embodiments described herein are solely for the purpose of illustration. The various features described herein need not all be used together, and any one or more of those features may be incorporated in a single embodiment. Therefore, persons skilled in the art will recognize from this description that other embodiments may be practiced with various modifications and alterations.