Abstract:
A memory device cooling apparatus includes a first heat sink operable to engage a first chip that is located on a memory device and that is operable to operate at a first temperature. A second heat sink is included that is separate from the first heat sink and is operable to engage a second chip that is located on a memory device and that is operable to operate at a second temperature, wherein the second temperature is different from the first temperature. A retaining feature is operable to couple the first heat sink and the second heat sink to a memory device. The memory device cooling apparatus may be coupled to a memory device having at least two different chips that operate at different temperatures to efficiently dissipate heat from the chips in order to cool the memory device.

Description:
BACKGROUND 
   The present disclosure relates generally to information handling systems, and more particularly to cooling a memory device in an information handling system. 
   As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option is an information handling system (IHS). An IHS generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes. Because technology and information handling needs and requirements may vary between different applications, IHSs may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in IHSs allow for IHSs to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, IHSs may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
   Most IHSs include memory devices that provides a processor with fast storage to facilitate the execution of computer programs. These memory devices include memory chips that heat up when the memory device is operated. The cooling of these memory devices raises a number of issues. 
   In some memory devices such as, for example, Fully Buffered Dual In-line Memory Modules (FBDIMMs), memory chips such as, for example, Advanced Memory Buffer (AMB) chips and Dynamic Random Access Memory (DRAM) chips, are used to accomplish the memory device functions. As the power of the AMB chips increases, the difference in operating temperatures between the DRAM chips and the AMB chips also increases. 
   A conventional method to cool the chips involves coupling a heat sink to the AMB chip and letting the DRAM chip dissipate its own heat. However, some solutions require additional cooling for the DRAM chips. In that situation, a heat sink plate may be coupled to the memory device that engages both the DRAM chips and the AMB chip. Such solutions are inefficient as the temperature difference between the AMB chip and the DRAM chip does not allow for optimal dissipation of heat for each of the chips with the heat sink plate engaging both the AMB chip and the DRAM chips. 
   Accordingly, it would be desirable to provide for cooling a memory device absent the disadvantages found in the prior methods discussed above. 
   SUMMARY 
   According to one embodiment, a memory device cooling apparatus includes a first heat sink operable to engage a first chip that is located on a memory device and that is operable to operate at a first temperature, a second heat sink that is separate from the first heat sink and is operable to engage a second chip that is located on a memory device and that is operable to operate at a second temperature, wherein the second temperature is different from the first temperature, and a retaining feature operable to couple the first heat sink and the second heat sink to a memory device. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view illustrating an embodiment of an IHS. 
       FIG. 2  is a perspective view illustrating an embodiment of a memory device. 
       FIG. 3  is a perspective view illustrating an embodiment of a first heat sink used with the memory device of  FIG. 2 . 
       FIG. 4  is a perspective view illustrating an embodiment of a second heat sink used with the memory device of  FIG. 2  and the first heat sink of  FIG. 3 . 
       FIG. 5  is a perspective view illustrating an embodiment of a first retaining member used with the memory device of  FIG. 2 , the first heat sink of  FIG. 3 , and the second heat sink of  FIG. 4 . 
       FIG. 6   a  is a flow chart illustrating an embodiment of method for cooling a memory device. 
       FIG. 6   b  is an exploded perspective view illustrating an embodiment of the assembly of the memory device of  FIG. 2 , the first heat sink of  FIG. 3 , the second heat sink of  FIG. 4 , and the retaining member of  FIG. 5 . 
       FIG. 6   c  is a perspective view illustrating an embodiment of a memory device cooling apparatus including the first heat sink of  FIG. 3 , the second heat sink of  FIG. 4 , and the retaining member of  FIG. 5  coupled to the memory device of  FIG. 2 . 
       FIG. 6   d  is a cross sectional view illustrating an embodiment of the memory device cooling apparatus of  FIG. 6   c  coupled to the memory device. 
       FIG. 7   a  is a perspective view illustrating an alternative embodiment of a component of a first heat sink used with the memory device of  FIG. 2 . 
       FIG. 7   b  is a perspective view illustrating an alternative embodiment of a component of a first heat sink used with the memory device of  FIG. 2 . 
       FIG. 8  is a perspective view illustrating an alternative embodiment of a second heat sink used with the memory device of  FIG. 2  and the first heat sink of  FIGS. 7   a  and  7   b.    
       FIG. 9   a  is a flow chart illustrating an embodiment of method for cooling a memory device. 
       FIG. 9   b  is an exploded perspective view illustrating an embodiment of the assembly of the memory device of  FIG. 2 , the first heat sink of  FIGS. 7   a  and  7   b , the second heat sink of  FIG. 8 , and the retaining member of  FIG. 5 . 
       FIG. 9   c  is a perspective view illustrating an embodiment of a memory device cooling apparatus including the first heat sink of  FIGS. 7   a  and  7   b , the second heat sink of  FIG. 8 , and the retaining member of  FIG. 5  coupled to the memory device of  FIG. 2 . 
   

   DETAILED DESCRIPTION 
   For purposes of this disclosure, an IHS may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, an IHS may be a personal computer, a PDA, a consumer electronic device, a network server or storage device, a switch router or other network communication device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The IHS may include memory, one or more processing resources such as a central processing unit (CPU) or hardware or software control logic. Additional components of the IHS may include one or more storage devices, one or more communications ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The IHS may also include one or more buses operable to transmit communications between the various hardware components. 
   In one embodiment, IHS  100 ,  FIG. 1 , includes a processor  102 , which is connected to a bus  104 . Bus  104  serves as a connection between processor  102  and other components of computer system  100 . An input device  106  is coupled to processor  102  to provide input to processor  102 . Examples of input devices include keyboards, touchscreens, and pointing devices such as mouses, trackballs and trackpads. Programs and data are stored on a mass storage device  108 , which is coupled to processor  102 . Mass storage devices include such devices as hard disks, optical disks, magneto-optical drives, floppy drives and the like. IHS system  100  further includes a display  110 , which is coupled to processor  102  by a video controller  112 . A system memory  114  is coupled to processor  102  to provide the processor with fast storage to facilitate execution of computer programs by processor  102 . In an embodiment, a chassis  116  houses some or all of the components of IHS  100 . It should be understood that other buses and intermediate circuits can be deployed between the components described above and processor  102  to facilitate interconnection between the components and the processor  102 . 
   Referring now to  FIG. 2 , a memory device  200  is illustrated. In an embodiment, the memory device  200  may be, for example, the system memory  114  described above with reference to  FIG. 1 . The memory device  200  includes a base  202  having a front surface  202   a , a rear surface  202   b  located opposite the front surface  202   a , a top edge  202   c  extending between the front surface  202   a  and the rear surface  202   b , a bottom edge  202   d  located opposite the top edge  202   c  and extending between the front surface  202   a  and the rear surface  202   b , and a pair of opposing side edges  202   e  and  202   f  extending between the front surface  202   a , the rear surface  202   b , the top edge  202   c , and the bottom edge  202   d . A plurality of first retaining member channels  204   a  and  204   b  are defined by the base  202   a  and located in a spaced apart orientation adjacent the top edge  202   c  of the base  202 , with the first retaining member channel  204   a  also located adjacent the side edge  202   e . A plurality of first retaining member channels  206   a  and  206   b  are defined by the base  202   a  and located in a spaced apart orientation adjacent the top edge  202   c  of the base  202 , with the first retaining member channel  206   b  also located adjacent the side edge  202   f . A second retaining member channel  208   a  is defined by the base  202  and located substantially centrally on the base  202   a  and adjacent the top edge  202   c . A second retaining member aperture  208   b  is defined by the base  202  and located substantially centrally on the base  202  and adjacent the bottom edge  202   d . A plurality of first chips  210  are coupled to and extend from the front surface  202   a  of the base  202  and are located along the length of the base  202  with the exception of the center of the base  202 . In an embodiment, a plurality of first chips  210  may also be coupled to and extend from the rear surface  202   b  of the base  202  (not shown). In an embodiment, the first chips  210  may be a variety of chips known in the art such as, for example, DRAM chips. In an embodiment, the first chips  210  are operable to operate at a temperature of approximately 85 degrees Celsius. In an embodiment, the first chips  210  are operable to operate in a temperature range of approximately 85-95 degrees Celsius. A second chip  212  is coupled to and extends from the front surface  202   a  of the base  202  and is located substantially centrally on the base  202  between the plurality of first chips  210 . In an embodiment, the second chip  212  may be a variety of chips known in the art such as, for example, an AMB chip. In an embodiment, the second chip  212  is operable to operate at a temperature of approximately  110  degrees Celsius. A heat transfer member  214  extends from the second chip  212 . 
   Referring now to  FIG. 3 , a first heat sink  300  is illustrated. The first heat sink  300  includes a first base member  302  having a front surface  302   a , a rear surface  302   b  located opposite the front surface  302   a , a top edge  302   c  extending between the front surface  302   a  and the rear surface  302   b , a bottom edge  302   d  located opposite the top edge  302   c  and extending between the front surface  302   a  and the rear surface  302   b , and a pair of opposing side edges  302   e  and  302   f  extending between the front surface  302   a , the rear surface  302   b , the top edge  302   c , and the bottom edge  302   d . A first retaining member channel  304  is defined by the first base member  302 , extends into the front surface  302   a  and the top edge  302   c , and is located adjacent the side edge  302   e . A first retaining member channel  306  is defined by the first base member  302 , extends into the front surface  302   a  and the top edge  302   c , and is located adjacent the side edge  302   f . A second heat sink aperture  308  is defined by the first base member  302 , is substantially centrally located on the first base member  302 , and extends through the first base member  302  from the front surface  302   a  to the rear surface  302   b . The first heat sink  300  also includes a second base member  310  having a front surface  310   a , a rear surface  310   b  located opposite the front surface  310   a , a top edge  310   c  extending between the front surface  310   a  and the rear surface  310   b , a bottom edge  310   d  located opposite the top edge  310   c  and extending between the front surface  310   a  and the rear surface  310   b , and a pair of opposing side edges  310   e  and  310   f  extending between the front surface  310   a , the rear surface  310   b , the top edge  310   c , and the bottom edge  310   d . A first retaining member channel  312  is defined by the second base member  310 , extends into the rear surface  310   b  and the top edge  310   c , and is located adjacent the side edge  310   e . A first retaining member channel  314  is defined by the second base member  310 , extends into the front surface  310   a  and the top edge  310   c , and is located adjacent the side edge  310   f . In an embodiment, the first heat sink  300  may be fabricated from copper, graphite, aluminum, and/or a variety of other heat sink materials known in the art. In an embodiment, the first heat sink  300  may include vapor chambers, heat pipes, and/or a variety of other heat dissipation components known in the art. In an embodiment, the first base member  302  and the second base member  310  may include heat dissipation components such as, for example, fins, heat pipes, and/or a variety of other heat dissipation components known in the art. 
   Referring now to  FIG. 4 , a second heat sink  400  is illustrated. The second heat sink  400  includes a base  402  having a front surface  402   a , a rear surface  402   b  located opposite the front surface  402   a , a top edge  402   c  extending between the front surface  402   a  and the rear surface  402   b , a bottom edge  402   d  located opposite the top edge  402   c  and extending between the front surface  402   a  and the rear surface  402   b , and a pair of opposing side edges  402   e  and  402   f  extending between the front surface  402   a , the rear surface  402   b , the top edge  402   c , and the bottom edge  402   d . A plurality of heat fins  404  extend from the front surface  402   a  of the base  402 . In an embodiment, the second heat sink  400  may be fabricated from copper, graphite, aluminum, and/or a variety of other heat sink materials known in the art. In an embodiment, the second heat sink  400  may include vapor chambers, heat pipes, and/or a variety of other heat dissipation components known in the art. 
   Referring now to  FIG. 5 , a first retaining member  500  is illustrated. The first retaining member  500  includes a substantially U-shaped base  502  having a front wall  502   a  and a rear wall  502   b  which are held in a spaced apart orientation by a top wall  502   c . The front wall  502   a  includes a bottom edge  502   aa  located opposite the top wall  502   c . The rear wall  502   b  includes a bottom edge  502   ba  located opposite the top wall  502   c . A first channel  504  is defined by the front wall  502   a , the rear wall  502   b , and the top wall  502   c  of the base  502  and is located substantially centrally on the base  502 . A retaining passageway  506  is defined between the front wall  502   a , the rear wall  502   b , and the top wall  502   c  of the base  502 . In an embodiment, the front wall  502   a  and the rear wall  502   b  are oriented with respect to each other such that the width of the top wall  502   c  is greater than the distance between the bottom edge  502   aa  of the front wall  502   a  and the bottom edge  502   ba  of the rear wall  502   b.    
   Referring now to  FIGS. 6   a ,  6   b ,  6   c  and  6   d , a method  600  for cooling a memory device is illustrated. The method  600  begins at step  602  where the memory device  200 , described above with reference to  FIG. 2 , is provided. The method  600  then proceeds to step  604  where the first chips  210  on the memory device  200  are engaged with the first heat sink  300 , described above with reference to  FIG. 3 , and the second chip  212  on the memory device  200  is engaged with the second heat sink  400 , described above with reference to  FIG. 4 . The second heat sink  400  is positioned adjacent the memory device  200  such that the rear surface  402   b  of the second heat sink  400  is located adjacent the heat transfer member  214  on the second chip  212 , as illustrated in  FIG. 6   b . The first base member  302  of the first heat sink  300  is positioned adjacent the memory device  200  such that the rear surface  302   b  of the first base member  302  is located adjacent the first chips  210  with the second heat sink  400  located between the first base member  302  and the memory device  200  and the second heat sink aperture  308  defined by the first base member  302  located adjacent the second heat sink  400 , as illustrated in  FIG. 6   b . The second base member  310  is positioned adjacent the memory device  200  such that the front surface  310   a  of the second base member  310  is located adjacent the rear surface  202   b  of the memory device  200 , as illustrated in  FIG. 6   b . The first base member  302  of the first heat sink  300  and the second heat sink  400  are then each moved in a direction A towards the memory device  200  such that the rear surface  302   b  of the first base member  302  engages the first chips  210 , the rear surface  402   b  on the second heat sink  402  engages the heat transfer member  214  on the second chip  212 , and the heat fins  404  on the second heat sink  400  extend through the second heat sink aperture  308 , as illustrated in  FIGS. 6   c  and  6   d . In an embodiment, a resilient member  604   a  engages the rear surface  302   b  of the first base member  302  on the first heat sink  300  and the front surface  402   a  on the second heat sink  400  such that the second heat sink  400  is moveably coupled to the first heat sink  300 , as illustrated in  FIG. 6   d . In an embodiment, the resilient member  604   a  is a leaf spring that is coupled to the front surface  402   a  of the second heat sink  400 . The second base member  310  of the first heat sink  310  is moved in a direction B towards the memory device  200  such that the front surface  310   a  of the second base member  310  engages the rear surface  202   b  of the memory device  200 , as illustrated in  FIGS. 6   c  and  6   d . In an embodiment, the front surface  310   a  of the second base member  310  engages a plurality of first chips  210  (not shown) located on the rear surface  202   b  of the memory device  200 . 
   The method  600  then proceeds to step  606  where the first heat sink  300  and the second heat sink  400  are coupled to the memory device  200  with a retaining device. In an embodiment, a retaining device includes a plurality of the first retaining members  500 , described above with reference to  FIG. 5 . The first retaining members  500  are positioned adjacent the memory device  200  and the first heat sink  300  and second heat sink  400  such that one first retaining member  500  is located adjacent the first retaining member channels  304  and  312  defined by the first base member  302  and the second base member  310 , respectively, and another first retaining member  500  is located adjacent the first retaining member channels  306  and  314  defined by the first base member  302  and the second base member  310 , respectively. The first retaining members  500  are then moved in a direction C such that the memory device  200 , the first base member  302  of the first heat sink  300 , and the second base member  310  of the first heat sink  300  are located in the retaining passageway  506  defined by the first retaining members  500 . With the memory device  200 , the first base member  302  of the first heat sink  300 , and the second base member  310  of the first heat sink  300  located in the retaining passageway  506  defined by the first retaining members  500 , the front wall  502   a  of one retaining member  500  is located in the first retaining member channel  304  defined by the first base member  302 , the rear wall  502   b  of that first retaining member  500  is located in the first retaining member channel  312  defined by the second base member  310 , and the top wall  502   c  of that first retaining member  500  is located in the first retaining member channels  204   a  and  204   b  defined by the memory device  200 , as illustrated in  FIG. 6   c . With the memory device  200 , the first base member  302  of the first heat sink  300 , and the second base member  310  of the first heat sink  300  located in the retaining passageway  506  defined by the first retaining members  500 , the front wall  502   a  of one retaining member  500  is located in the first retaining member channel  306  defined by the first base member  302 , the rear wall  502   b  of that first retaining member  500  is located in the first retaining member channel  314  defined by the second base member  310 , and the top wall  502   c  of that first retaining member  500  is located in the first retaining member channels  206   a  and  206   b  defined by the memory device  200 , as illustrated in  FIG. 6   c . With the first retaining member  500  coupling the first heat sink  300  and the second heat sink  400  to the memory device  200 , the stiffness of the memory device  200  is increased. 
   The method  600  then proceeds to step  608  where the memory device  200  is cooled. The memory device  200  with the first heat sink  300  and the second heat sink  400  coupled to it may be coupled to a processor such as, for example, the processor  102 , described above with reference to  FIG. 1 , using methods known in the art for use with an IHS such as, for example, the IHS  100 , described above with reference to  FIG. 1 . During operation of the memory device  200 , the first chips  210  will operate at a first temperature and the second chip  212  will operate at a second temperature that is different from the first temperature. The first heat sink  300  will dissipate heat from the first chips  210  and the second heat sink  400  will dissipate heat from the second chip  212 . Due to the weak thermal coupling between the first heat sink  300  and the second heat sink  400 , the dissipation of heat from the first chips  210  and the second chip  212  is more efficient than conventional memory device cooling apparatus as heat from the first chips  210  does not effect the second heat sink  400  and heat from the second chip  212  does not effect the first heat sink  300 . Thus, a method and apparatus are provided which allow efficient thermal dissipation for a memory device having a first chip and a second chip that operate at different temperatures. 
   Referring now to  FIGS. 7   a  and  7   b , an alternative embodiment of a first heat sink  700  is illustrated. The first heat sink  700  includes a first base member  702  having a front surface  702   a , a rear surface  702   b  located opposite the front surface  702   a , a top edge  702   c  extending between the front surface  702   a  and the rear surface  702   b , a bottom edge  702   d  located opposite the top edge  702   c  and extending between the front surface  702   a  and the rear surface  702   b,  and a pair of opposing side edges  702   e  and  702   f  extending between the front surface  702   a , the rear surface  702   b , the top edge  702   c , and the bottom edge  702   d . The first heat sink  700  also includes a second base member  704  having a front surface  704   a , a rear surface  704   b  located opposite the front surface  704   a , a top edge  704   c  extending between the front surface  704   a  and the rear surface  704   b , a bottom edge  704   d  located opposite the top edge  704   c  and extending between the front surface  704   a  and the rear surface  704   b , and a pair of opposing side edges  704   e  and  704   f  extending between the front surface  704   a , the rear surface  704   b , the top edge  704   c , and the bottom edge  704   d . A coupling member  706  extends from the side edge  704   e  of the second base member  704  and out past the front surface  704   a  of the second base member  704 . A coupling member  708  extends from the side edge  704   f  of the second base member  704  and out past the front surface  704   a  of the second base member  704 . In an embodiment, the first base member  702  and the second base member  704  may be fabricated from copper, graphite, aluminum, and/or a variety of other heat sink materials known in the art. In an embodiment, the first base member  702  and the second base member  704  may include vapor chambers, heat pipes, and/or a variety of other heat dissipation components known in the art. In an embodiment, the first base member  702  and the second base member  704  may include heat dissipation components such as, for example, fins, heat pipes, and/or a variety of other heat dissipation components known in the art. 
   Referring now to  FIG. 8 , an alternative embodiment of a second heat sink  800  is illustrated. The second heat sink  800  includes a base  802  having a front surface  802   a , a rear surface  802   b  located opposite the front surface  802   a , a top edge  802   c  extending between the front surface  802   a  and the rear surface  802   b , a bottom edge  802   d  located opposite the top edge  802   c  and extending between the front surface  802   a  and the rear surface  802   b , and a pair of opposing side edges  802   e  and  802   f  extending between the front surface  802   a , the rear surface  802   b , the top edge  802   c , and the bottom edge  802   d . A second retaining member channel  804   a  is defined by the base  802 , extends through the base from the front surface  802   a  to the rear surface  802   b  and down from the top edge  802   c , and is substantially centrally located on the top edge  802   c  of the base  802 . A second retaining member channel  804   b  is defined by the base  802 , extends through the base from the front surface  802   a  to the rear surface  802   b  and up from the bottom edge  802   d , and is substantially centrally located on the bottom edge  802   d  of the base  802 . A heat dissipation wall  806  extends from the side edge  802   e  of the base  802 . A heat dissipation wall  808  extends from the side edge  802   f  of the base  802 . In an embodiment, the second heat sink  800  may be fabricated from copper, graphite, aluminum, and/or a variety of other heat sink materials known in the art. In an embodiment, the second heat sink  800  may include vapor chambers, heat pipes, and/or a variety of other heat dissipation components known in the art. In an embodiment, the base  802  may include heat dissipation components such as, for example, fins, heat pipes, and/or a variety of other heat dissipation components known in the art. 
   Referring now to  FIGS. 9   a ,  9   b  and  9   c , a method  900  for cooling a memory device is illustrated. The method  900  begins at step  902  where the memory device  200 , described above with reference to  FIG. 2 , is provided. The method  900  then proceeds to step  904  where the first chips  210  on the memory device  200  are engaged with the first heat sink  700 , described above with reference to  FIGS. 7   a  and  7   b . A plurality of the first base members  702  of the first heat sink  300  are positioned adjacent the memory device  200  such that the rear surfaces  702   b  of the first base members  702  are adjacent the first chips  210 , as illustrated in  FIG. 6   b . The second base member  704  is positioned adjacent the memory device  200  such that the front surface  704   a  of the second base member  704  is located adjacent the rear surface  202   b  of the memory device  200 , as illustrated in  FIG. 6   b . The first base members  702  of the first heat sink  700  are then each moved in a direction D towards the memory device  200  such that the rear surface  702   b  of the first base members  702  engage the first chips  210 , as illustrated in  FIGS. 6   c  and  6   d . The second base member  704  of the first heat sink  700  is moved in a direction E towards the memory device  200  such that the front surface  704   a  of the second base member  704  engages the rear surface  202   b  of the memory device  200 , as illustrated in  FIGS. 6   c  and  6   d . In an embodiment, the front surface  704   a  of the second base member  704  engages a plurality of first chips  210  (not shown) located on the rear surface  202   b  of the memory device  200 . 
   The method  900  then proceeds to step  906  where the first heat sink  700  is coupled to the memory device  200  with a retaining device. In an embodiment, a retaining device includes a plurality of the first retaining members  500 , described above with reference to  FIG. 5 . The first retaining members  500  are positioned adjacent the memory device  200  and the first heat sink  700  such that they are located adjacent the first base member  702  and the second base member  704 . The first retaining members  500  are then moved in a direction F such that the memory device  200 , the first base member  702  of the first heat sink  700 , and the second base member  704  of the first heat sink  700  are located in the retaining passageway  506  defined by the first retaining members  500 . With the memory device  200 , the first base member  702  of the first heat sink  700 , and the second base member  704  of the first heat sink  700  located in the retaining passageway  506  defined by the first retaining members  500 , the front wall  502   a  of one retaining member  500  engages the first base member  702 , the rear wall  502   b  of that first retaining member  500  engages the second base member  7004 , and the top wall  502   c  of that first retaining member  500  is located in the first retaining member channels  204   a  and  204   b  defined by the memory device  200 , as illustrated in  FIG. 9   c . With the memory device  200 , the first base member  702  of the first heat sink  700 , and the second base member  704  of the first heat sink  700  located in the retaining passageway  506  defined by the first retaining members  500 , the front wall  502   a  of one retaining member  500  engages the first base member  702 , the rear wall  502   b  of that first retaining member  500  engages the second base member  704 , and the top wall  502   c  of that first retaining member  500  located in the first retaining member channels  206   a  and  206   b  defined by the memory device  200 , as illustrated in  FIG. 9   c.    
   The method  900  then proceeds to step  908  where the second chip  212  on the memory device  200  is engaged with the second heat sink  800 , described above with reference to  FIG. 8 . The second heat sink  800  is positioned adjacent the memory device  200  such that the rear surface  802   b  of the second heat sink  800  is located adjacent the heat transfer member  214  on the second chip  212 , as illustrated in  FIG. 9   b . The second heat sink  800  is then moved in the direction D such that the rear surface  802   b  of the second heat sink  800  engages the heat transfer member  214  on the second chip  212 . The method  900  then proceeds to step  910  where the second heat sink  800  is coupled to the memory device  200  with a retaining device. In an embodiment, a retaining device includes a second retaining member  910   a . The second retaining member  910   a  is coupled to the memory device  200  and the second heat sink  800  by engaging the second retaining member channel  208   a  and the second retaining member aperture  208   b  defined by the memory device  200 , and engaging the second retaining member channels  804   a  and  804   b  and the front surface  802   a  of the second heat sink  800  with second retaining member  910   a , as illustrated in  FIG. 9   c.    
   The method  900  then proceeds to step  912  where the memory device  200  is cooled. The memory device  200  with the first heat sink  700  and the second heat sink  800  coupled to it may be coupled to a processor such as, for example, the processor  102 , described above with reference to  FIG. 1 , using methods known in the art for use with an IHS such as, for example, the IHS  100 , described above with reference to  FIG. 1 . During operation of the memory device  200 , the first chips  210  will operate at a first temperature and the second chip  212  will operate at a second temperature that is different from the first temperature. The first heat sink  700  will dissipate heat from the first chips  210  and the second heat sink  800  will dissipate heat from the second chip  212 . Due to the weak thermal coupling between the first heat sink  700  and the second heat sink  800 , the dissipation of heat from the first chips  210  and the second chip  212  is more efficient than conventional memory device cooling apparatus as heat from the first chips  210  does not effect the second heat sink  800  and heat from the second chip  212  does not effect the first heat sink  700 . Thus, a method and apparatus are provided which allow efficient thermal dissipation for a memory device having a first chip and a second chip that operate at different temperatures. 
   Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.