Abstract:
A heat sink retention apparatus includes a frame for supporting a heat sink. A plurality of flexible members extend from opposite ends of the frame. Each flexible member includes a retention tab and one of the retention tabs includes a retraction tab. A heat sink is snapped-into the frame by engaging either of the retention tabs and flexing the other retention tab. The retraction tab can be flexed to disengage one of the retention tabs for extracting the heat sink from the frame.

Description:
BACKGROUND 
     The present disclosure relates generally to information handling systems, and more particularly to heat sink retention in such systems. 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs is and requirements vary between different users or applications, information handling systems 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 information handling systems allow for information handling systems 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, information handling systems 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. 
     New processors are requiring larger and heavier heatsink/fansink solutions, which have created additional complexity during manufacture. In order to preserve contact between the processor die and the heat sink, the fastener solutions create a large amount of preload force and, as a consequence, the fastener has become complicated to assemble. The difficulty in assembly of current solutions also causes ergonomic issues to assemblers and is very difficult to disassemble. As the complexity of the heat sink and retention mechanisms increases, the number/cost of parts and time to assemble has also increased. 
     One solution uses metal leaf springs placed on each side of the heat sink, attached to plastics bases. This method creates an accessibility issue inside the chassis creating four areas that need to be accessed in order to assemble and disassemble the heat sink. This drives cost into the system. 
     Another solution provides metal clips that span across the middle of the heat sink and attach to the middle socket. This creates a single contact area on the sink allowing excessive wobble of the sink. The attachment method to current sockets is unsatisfactory. 
     A further solution uses single lever mechanism to actuate a torsion system that rotates into place retaining the heat sink against shock events during shipping. The actuation of the torsion system is created by a Geneva gear mechanism that locks the system from rotation at its lower and upper position. 
     Therefore, what is needed is a heat sink retention device that provides a balanced load on the heat sink, reduces the number of parts required, is cost efficient and decreases assembly time. 
     SUMMARY 
     One embodiment, accordingly, provides a heat sink retention apparatus including a frame for supporting a heat sink. A plurality of flexible members extend from opposite ends of the frame. Each flexible member includes a retention tab. At least one of the retention tabs includes a retraction tab. 
     A principal advantage of this embodiment is that the springs can be balanced to provide equal pressure. The number of parts required is reduced. The cost is low and the device requires decreased assembly time. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic view illustrating an embodiment of a computer system. 
     FIG. 2 is a perspective view illustrating an embodiment of a chassis including a heat sink. 
     FIG. 3 is a side view illustrating an embodiment of a frame member. 
     FIG. 4 is a side view illustrating an embodiment of the frame member supporting and retaining the heat sink. 
     FIG. 5 is a perspective view illustrating an embodiment of the frame member. 
     FIGS. 6-8 are side views Illustrating an embodiment of the heat sink being seated and/or removed from the frame member. 
    
    
     DETAILED DESCRIPTION 
     For purposes of this disclosure, an information handling system 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, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory is (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network 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 information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     In one embodiment, computer system  10 , FIG. 1, includes a microprocessor  12 , which is connected to a bus  14 . Bus  14  serves as a connection between microprocessor  12  and other components of computer system  10 . An input device  16  is coupled to microprocessor  12  to provide input to microprocessor  12 . 
     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  18 , which is coupled to microprocessor  12 . Mass storage devices include such devices as hard disks, optical disks, magneto-optical drives, floppy drives and the like. Computer system  10  further includes a display  20 , which is coupled to microprocessor  12  by a video controller  22 . A system memory  24  is s coupled to microprocessor  12  to provide the microprocessor with fast storage to facilitate execution of computer programs by microprocessor  12 . It should be understood that other busses and intermediate circuits can be deployed between the components described above and microprocessor  12  to facilitate interconnection between the components and the microprocessor. 
     Microprocessor  12  is mounted on a motherboard  26  in a chassis  28 , FIG. 2, which may be a chassis of various form factors. A frame member  30  is mounted on motherboard  26  in chassis  28  such that the frame member  30  is positioned adjacent the microprocessor  12  so as to support a heat sink  32 , seated in contact with the microprocessor  12 , discussed below. 
     Chassis  28 , FIG. 2, supports several of the components of computer system  10 . In addition, motherboard  26  is mounted in chassis  28  and a support base  34 , FIG. 3, is mounted on and electrically connected to the motherboard  26 . Microprocessor  12  is mounted on the support base  34 . A heat spreader  36  is a portion of the microprocessor  12  through which heat generated by the microprocessor  12  is concentrated for contact with heat sink  32 , FIG.  4 . 
     Frame member  30 , FIG. 5, is generally rectangular and includes a pair of opposed end members  38   a ,  38   b  interconnected with a pair of opposed side members  40   a ,  40   b  at a plurality of comer columns  42  to form a surface  39  for supporting heat sink  32 . A pair of flexible member beams  44  each extend between two of the columns  42 . One of the flexible members  44  is adjacent the end member  38   a  and the other flexible member  44  is adjacent the end member  38   b . It should be understood that each flexible member  44  could alternatively be an extension of a respective end member  38   a  and  38   b.    
     Each flexible member  44  includes a retention tab  46  and at least one of the retention tabs  46  includes a retraction tab  48 . Each retention tab  46  includes a pair of opposed ramp surfaces  50  and  52 , FIGS. 6 and 7. The ramp surface  50  is opposed to ramp surface  52  in that ramp surface  50  is on a first side  46   a  of retention tab  46  and ramp surface  52  is on a second side  46   b  of retention tab  46 . The retraction tab  48  extends from one of the retention tabs  46 . 
     In operation, each opposite end  60  and  62  of heat sink  32 , FIGS. 6,  7  and  8 , includes a chamfer  63  and a substantially flat surface  64 . One end  60 , FIG. 6, of heat sink  32  is inserted at an angle to toe in to frame member  30  so that one flat surface  64  engages side  46   a  of one of the retention tabs  46 . In this position, the other end  62  of heat sink  32 , positions its respective chamfer  63  in engagement with ramp  52  of an opposite retention tab  46 . A downward force in a direction D 1 , FIG. 7, urges end  62  to flex the opposite retention tab  46  outwardly in a direction W 1 . Still further downward force in direction D 1 , FIG. 8, urges end  62  to engage ramp  50  which further urges end  62  downward to clear the opposite retention tab  46 . Finally, flat surface  64  is engaged when side  46   a  of retention tab  46  moves inwardly in a direction W 2 , so that each end  60  and  62  of heat sink  32  is retained by a downward, or D 1 , force due to engagement with retention tabs  46 . 
     For removal, manual flexure of retraction tab  48 , FIG. 7, in the outwardly direction W 1 , will displace retention tab  46  sufficiently to permit end  62  of heat sink  32  to be lifted in a direction L 1  to permit heat sink  32  to be removed from frame member  30 . 
     In summary, the present device comprises a single molded plastic part that provides a balanced load on the heat sink. The heat sink is placed into the frame at an angle to “toe in” using ramping forces (chamfers) to lift the plastic spring. The opposite end of the heat sink is forced into the plastic frame deflecting the second plastic spring out and then up using ramping forces. Each spring end has two motions;  1 ) outward to provide clearance for the heat sink, and inward to lift the spring to capture the heat sink and position the spring to provide downward force; and  2 ) downward to provide the clamping force required to hold the heat sink in place. 
     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.