Abstract:
An apparatus and system are disclosed for securing a heat sink against a central processing unit. The present invention teaches a heat sink securement device having a vertical retention arm that substantially encompasses a heat sink in a vertical direction, a horizontal retention arm that substantially encompasses a heat sink in a horizontal direction, and a tension arm coupled to the vertical and horizontal retention arms and pivotally coupled to the frame, the tension arm simultaneously adjusts a tension on the vertical retention arm and the horizontal retention arm in response to moving the tension arm. In certain embodiments, the retention arms are coupled to the tension arm via coupling member that is offset from pivot point of the tension arm. In other embodiments, the coupling member may include a different coupling member for the vertical and horizontal retention arms, both coupling members offset from the pivot point.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application is a continuation and claims priority to U.S. patent application Ser. No. 11/319,900 entitled “APPARATUS, SYSTEM, AND METHOD TO SECURE A HEAT SINK” and filed on Dec. 28, 2005 for Richard M. Barina, which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to systems, methods, and apparatuses for handling and packaging high performance integrated circuits such as central processing units (CPUs) and more particularly relates to systems, methods, and apparatuses for securing a heat sink against a high performance integrated circuit. 
   2. Description of the Related Art 
   Proper heat sink performance has become an increasingly important subject as a result of the increased device density on integrated circuits and increase packaging density on printed circuit boards. The fundamental role of a heat sink is to cool an integrated circuit by receiving heat from the integrated circuit and transferring the heat to the environment. One example of an integrated circuit that may significantly benefit from cooling is a central processing unit (CPU). Reducing the temperature of the integrated circuit is critical to the performance and life of the CPU. If the heat sink, for some reason, shifts away from the CPU, then the functionality of the integrated circuit is compromised as overheating will inevitably occur. Accordingly, maintaining the proper positioning of the heat sink against the integrated circuit is paramount to ensuring properly function integrated circuits such as CPUs. 
   In an attempt to ensure proper position of the heat sink, certain approaches been developed. For example, adhesives or epoxy-type grease are sometimes used to thermally join the heat sink to the integrated circuit. Though a simple adhesive may maintain the proper positioning of the heat sink under ideal conditions, during shipment or relocation of the computer, an adhesive may prove insufficiently strong in light of the bumps and shifts of transporting the device. Moreover, the bumps and shifts associated with transporting a computer may be even more of a problem when the heat sink is relatively massive and the need for thermal dissipation is greatest. 
   Other devices for securing a heat sink to an integrated circuit include complex systems with multiple removable parts. Such systems include screws, brackets, latches, and other mechanisms that may require considerable time to understand and use. Moreover, because these complex systems use removable parts, the probability of loosing a part essential to securing a heat sink is substantially increased. 
   From the foregoing discussion, it should be apparent that a need exists for an improved system, apparatus, and method for securing a heat sink to a high performance integrated circuit such as a CPU. Beneficially, such a system, apparatus and method would substantially increase the probability of proper heat sink positioning in addition to enabling simple heat sink insertion, securement, and removal. 
   SUMMARY OF THE INVENTION 
   The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available solutions. Accordingly, the present invention has been developed to provide an apparatus, system, and method for securing a heat sink against an integrated circuit that overcome many or all of the above-discussed shortcomings in the art. 
   The present invention in the described embodiments include a frame, a vertical retention arm that substantially encompasses a heat sink in a vertical direction, a horizontal retention arm configured to substantially encompass a heat sink in a horizontal direction, and a tension arm coupled to the vertical and horizontal retention arms and pivotally coupled to the frame. The tension arm simultaneously adjusts a tension on the vertical retention arm and the horizontal retention arm in response to moving the tension arm. The various components of the present invention cooperate to secure a heat sink against an integrated circuit such as CPU. 
   In certain embodiments, the tension arm includes a coupling member that couples the vertical retention arm and the horizontal retention arm to the tension arm. In certain embodiments, the coupling member may be a loop. In some embodiments, the coupling member may be offset from a pivot point of the tension arm. Additionally, the coupling member may trace a substantially semi-circular path in response to adjusting the tension arm. In some embodiments the vertical retention arm is pivotally coupled to the tension arm. In certain embodiments, the frame comprises a horizontal brake configured to oppose horizontal motion of a heat sink. 
   A system of the present invention is also presented for securing a heat sink against an integrated circuit. The system may be embodied as an integrated circuit, a frame, a heat sink, and a heat sink securement device in accordance with the present invention. In certain embodiments, the system may also include a printed circuit board and a computer chassis. 
   A method of the present invention is also presented for securing a heat sink against an integrated circuit. The method in the disclosed embodiments substantially includes the operations necessary to carry out the functions presented above with respect to the operation of the described apparatus and system. In one embodiment, the method includes providing a frame, substantially encompassing a heat sink in a vertical direction with a vertical retention arm, substantially encompassing a heat sink in a horizontal direction with a horizontal retention arm, coupling the vertical and horizontal retention arms with a tension arm pivotally coupled to the frame, and simultaneously adjusting the tension on the vertical retention arm and the horizontal retention arm by moving the tension arm. 
   Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
   Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. These features and advantages will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
       FIG. 1  is a perspective view of one embodiment of a heat sink securement system in accordance with the present invention; 
       FIG. 2  is a perspective view of one embodiment of a heat sink securement apparatus in accordance with the present invention 
       FIG. 3A-3E  are perspective views of one embodiment of a heat sink securement apparatus in accordance with the present invention; 
       FIG. 4  is a schematic flow diagram illustrating one embodiment of a method for securing a heat sink to a against a central processing unit in accordance with the present invention; and 
       FIG. 5  is a perspective view of one embodiment of a heat sink securement apparatus in accordance with the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
   Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
     FIG. 1  is a perspective view of one embodiment of a heat sink securement system  100 . The depicted system  100  includes a chassis  110 , a circuit board  120 , a heat sink  130 , a frame  140 , a vertical retention arm  150 , a tension arm  160 , and a horizontal retention arm  170 . The system  100  may also include a high performance integrated circuit such as a CPU (see  FIG. 3 ) positioned underneath the heat sink  130 . In certain embodiments, the system  100  may also include a thermally conductive adhesive or grease between the heat sink  130  and the integrated circuit. The various components of the system  100  function cooperatively to secure the heat sink  130  against the integrated circuit. 
   As will be further detailed in subsequent figures, the vertical retention arm  150  and horizontal retention arm  170  secure the heat sink  130  to the frame  140 . The tension arm  160  adjusts the tension of the vertical and horizontal retention arms  150 ,  170 . The frame  140  provides horizontal and vertical boundaries against which the vertical and horizontal arms  150 ,  170  may secure the heat sink  130 . 
   The frame  140  may be secured to the chassis  110  and, by implication to the circuit board  120  (see  FIG. 2  for more detail). Securing the frame  140  to the chassis  110  instead of the circuit board  120  ensures the stability of overall system  100  in addition to avoiding unnecessary stress on the circuit board  120 . The frame  140  may be positioned and secured with respect to the circuit board  120  and chassis  110  such that the heat sink  130  may be secured against the integrated circuit (see  FIG. 3 ) once the heat sink  130  is inserted into the frame  140 . A power supply (not shown) may provide power to the electronic components of the system  100 . 
   The heat sink  130  cools the operating temperature of the integrated circuit by receiving dissipating heat from the integrated circuit (see  FIG. 3 ). The heat sink  130  may include any variety of heat sink models, types, or makes including heat sinks made of a thermally conductive material such as copper or aluminum. In certain embodiments, the heat sink weighs approximately two (2) to three (3) pounds. The chassis  110  provides stability to the overall system  100 . The present invention is not limited to a type or model of chassis, as would be understood by one of skill in the art. 
   Similarly, the present invention is not limited to a type or model of circuit board, processor board, mother board, etc. Rather, the circuit board  120  may comprise any variety of circuit boards having need of a heat sink. In certain embodiments, the circuit board  120  is sufficiently stiff so as to withstand the downward pressure of the secured heat sink  130  and not bend or contort, and thereby create a space between the heat sink  130  and the integrated circuit. In other embodiments, the circuit board  120  may be supported by the chassis  110  to deter such bending or contortion. Accordingly, the features and details of the circuit board  120  are meant only for illustrate purpose of the general concept of a circuit board. 
     FIG. 2  is a perspective view of one embodiment of a heat sink securement apparatus  200 . The depicted apparatus  200  includes a frame  210 , a vertical retention arm  220 , a tension arm  230 , and a horizontal retention arm  240 . The frame  210 , the vertical retention arm  220 , the tension arm  230 , and the horizontal retention arm  240  enable insertion, securement, and removal of the heat sink  130 . 
   The vertical retention arm  220  vertically secures the heat sink  130  to the frame  210 . The horizontal retention arm  240  horizontally secures the heat sink  130  against the back bracket  214  of the frame  210 . The frame  210  may also include lateral brackets  212  for securing the heat sink  130  laterally within the frame  210 . 
   In certain embodiments, the frame  210  may also include break  242  for horizontal stabilization of the heat sink  130 . In such embodiments, the inward, horizontal motion of the horizontal retention arm  240  may push, slide, rock, or otherwise shift the break  242  horizontally to engage the heat sink  130 . The arms  220 ,  230 , and  240 , may be of a variety of materials including stainless steel. Similarly, the frame  210  may be made of a variety of sufficiently strong materials including aluminum or zinc. Accordingly, the retention arms  220 ,  240  and the frame  210  cooperate to secure the heat sink  130  (see  FIG. 1 ) vertically, horizontally, and laterally. 
   The tension arm  230  adjusts the tension of the vertical retention arm  220  and horizontal retention arm  240 . In certain embodiments, the total pressure upon the secured heat sink  130  is approximately ten (10) to forty (40) pounds per square inch (psi). The tension arm  230  is pivotally coupled  260  to the frame  210 . The tension arm  230  includes a coupling member such as a loop that is offset from the pivot point  260 . The vertical and horizontal retention arms  220 ,  240  are coupled to the loop  250  of the tensions arm  230 . Consequently, the tension of the retention arms  220 ,  240  adjust according to the rotation of the tension arm  230  and the relative position of the coupling loop  250  to the pivot point  260 . 
   The frame  210  may be secured to the chassis in various ways including the use of stand off legs  216 . In certain embodiments, the stand off legs  216  of the frame  210  engage the stand offs of the chassis  110  (see  FIG. 1 ). As suggested in the description of  FIG. 1  above, securing the frame  140  to the chassis  110  instead of the circuit board  120  ensures the stability of overall system  100  in addition to avoiding unnecessary stress on the circuit board  120 . 
     FIGS. 3   a - 3   e  are perspective views of one embodiment of a heat sink securement apparatus  300 . The depicted  FIGS. 3   a - 3   e  viewed sequentially illustrate the insertion and securement of a heat sink  350  within the heat sink securement apparatus  300 . Removal of the heat sink  350  includes a reversal of the insertion and securement steps. For purposes of differentiation between various element positions, each element identifier in the following discussion as appended with a letter that matches the corresponding Figure. 
   Referring to  FIG. 3   a , the heat sink  350   a  may be inserted into frame  310   a  via the direction  352   a . The vertical retention arm  320   a , the horizontal retention arm  340   a , and the tension arm  330   a  are in a substantially horizontal position to provide sufficient space whereby the heat sink  350   a  may be inserted into the frame  310   a . Consequently, the loop  332   a  of the tension arm  330   a  is rotated substantially downward with respect to the pivot point  334   a . When fully inserted, the heat sink  350   a  resides within the frame  310   a . In certain embodiments, the bottom surface of the heat sink  350   a  does not touch the frame  310   a , but sits on top of the integrated circuit  360   a  instead. 
   Referring to  FIG. 3   b , once the heat sink  350   b  is positioned within the frame  310   b , the vertical retention arm  320   b  and the tension arm  330   b  may be rotated upward in the direction  370   b . As depicted in  FIG. 3   c , the vertical arm  320   c  and tension arm  330   c  may be rotated to a substantially vertical position. It should be noted that the loop  332   c  of the tension arm  330   c  similarly rotates from a downward position (see  FIG. 3   a ) to a position more horizontal with the pivot point  334   c . Consequently, as the vertical retention arm  320   c  is coupled to the loop  332   c  of the tension arm  330   c , the vertical retention arm  320   c  shifts upward in the direction  372   c . Similarly, because the horizontal retention arm  340   c  is coupled to the loop  332   c , the horizontal retention arm  340   c  shifts in the direction  374   c  as the loop  332   c  is now in a more horizontal position than seen in  FIG. 3   b.    
   Referring to  FIG. 3   d , once the vertical arm  320   d  is in a substantially vertical position, the tension arm  330   d  may be rotated downward in the direction  336   d  which in turn rotates the loop  332   d  in the direction and lowers the vertical retention arm  320   d  in the direction  382   d , to secure the heat sink  350   d  vertically against the integrated circuit  360   a  (see  FIG. 3   a ). In addition to shifting the position of the vertical arm  320   d , rotating the tension arm  330   d  also shifts the horizontal retention arm  340   d  and, consequently, the break  342   d , in the direction  384   d . In certain embodiments, the pivotal coupling relationship between the vertical retention arm  320   d , the tension arm  330   d , and the horizontal retention arm  340   d  is such that, when the tension arm  330   d  is rotated downward in the direction  336   d , the vertical retention arm  320   d  actually engages and secures the heat sink  350   d  vertically before the horizontal retention arm  340   d  and break  342   d  engage the heat sink  350   d  horizontally. 
   As seen in  FIG. 3   e , once the tension arm  330   e  is in a substantially horizontal position as depicted, the position of the loop  332   e  is such that both the vertical and horizontal retention arms  320   e ,  240   e  are applying pressure against the heat sink  350   e  and thereby securing the heat sink  350   e  to the integrated circuit  360   a  (see  FIG. 3   a ). It should be noted that the depicted position of the loop  332   e  is beyond the point of maximum vertical tension corresponding to the illustrative line  392   e  which vertically intersects the pivot point  334   e . In a position beyond the point of maximum tension, if vertical outward pressure is placed upon the heat sink  350   e , the pivot  334   e  and loop  332   e  will tend to rotate in the direction  390   e . However, such rotation is inhibited since the tension arm  330   e  cannot rotate any further. In other words, because the loop  332   e  has rotated beyond the center of the pivot point  334   e , applying outward, vertical pressure on the heat sink  350   e  essentially locks the heat sink  350   e  within the frame  310   e . Having the loop  332   e  offset from the pivot point  334   e  of the tension arm  330   e  provides a point of maximum tension and a locking effect for positions beyond the point of maximum tension. A horizontal version of this beyond center principle is taught and enabled specifically in  FIG. 5 . 
     FIG. 4  is a schematic flow diagram illustrating one embodiment of a method for securing a heat sink  350   a  against an integrated circuit  360   a . The depicted method  400  includes providing  410  a frame, vertically encompassing  420  a heat sink with a vertical retention arm, horizontally encompassing  430  the heat sink with a horizontal retention arm, coupling  440  the vertical and horizontal retention arms with a tension arm, adjusting  450  the vertical and horizontal tension arms with the tension arm. The steps in the depicted method  400  function to secure a heat sink against a CPU. 
   In certain embodiments, coupling  440  the vertical and horizontal retention arms with a tension arm includes coupling the vertical and horizontal retention arms with a coupling member of the tension arm. In certain embodiments, the coupling member may be a loop. The coupling member may be offset from a pivot point of the tension arm to enable an over the center feature of the tension arm. Additionally, as depicted, the coupling member may follow a substantially semi-circular path in response to engaging the tension arm. 
   Vertically restraining  420  a heat sink in a vertical direction with a vertical retention arm may include using a vertical retention arm that is pivotally coupled to the tension arm. Horizontally restraining  430  a heat sink with a horizontal retention arm may include using a horizontal retention arm that is coupled to the tension arm. In certain embodiments, providing a frame  410  includes providing a horizontal brake configured to oppose horizontal motion of a heat sink. 
     FIG. 5  is a perspective view of one embodiment of a heat sink securement apparatus  500 . The depicted apparatus  500  includes an integrated circuit base  510 , a vertical retention arm  520 , a tension arm  530 , and a horizontal retention arm  540 . The tension arm  530  also includes a first coupling member, in the form of a loop  532 , for coupling the vertical retention arm  520 . The loop  532  pivots about the pivot point  534  as the tension arm  530  is rotated. The vertical retention arm  520  also includes a coupling member in the form of a second loop  526  for coupling the horizontal retention arm  540 . 
   As the horizontal retention arm  540  is coupled to the vertical retention arm  520 , as the vertical retention arm  520  is originally rotated from a substantially horizontal position (see  FIG. 3   a ) to a substantially vertical position (as depicted) the horizontal arm adjust according to the changing position of the second loop  526  and is, consequently, adjusted horizontally inward to the current depicted position. Because the horizontal retention arm  540  is coupled to the secured vertical retention arm  520  above the pivot point  534  of the tension arm  530 , any outward horizontal pressure will further secure the heat sink to the frame  510  because the point of maximum tension of the vertical arm as explained in  FIG. 3   e.    
   The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.