Retaining assembly for heat sink

[0002] 1. Field of the Invention

[0003] The present invention relates to a retaining assembly for a heat sink, and particularly to a retaining assembly which restricts unwanted lateral movement of the heat sink and maintains good contact between the heat sink and an associated heat-generating device such as a central processing unit (CPU).

[0004] 2. Description of the Related Art

[0005] With the development of electronics and computer technology, many electronic components have become highly integrated and very powerful. A typical such component is a CPU, and heat generated by modern CPUs is considerable. Excessive heat can adversely affect the operational stability of CPUs. Typically, a heat sink is mounted on a CPU to dissipate heat therefrom. This ensures normal operation of the CPU.

[0006] A conventional means of fastening a heat sink to a CPU uses a clip. However, retaining force acting on the heat sink is generally in vertical directions only. The heat sink is liable to be displaced in lateral directions when it is subjected to vibration or shock during normal use. For a typical Land Grid Array (LGA) CPU, the CPU is connected to an LGA socket by a plurality of elastic pads. If the heat sink is displaced a considerable distance, the CPU is prone to be separated from the socket thereby disrupting electrical connection between the CPU and the socket. For a typical Pin Grid Array (PGA) CPU, the CPU is connected to a CPU socket by a plurality of pins. This configuration can tolerate lateral sliding to a certain extent. However, if the heat sink greatly is displaced a considerable distance, the CPU is still prone to be separated from the socket thereby disrupting electrical connection between the CPU and the socket.

[0007] To overcome these problems, a heat sink retaining device which prevents lateral sliding of a heat sink is desired.

[0008] Accordingly, an object of the present invention is to provide a heat sink retaining assembly which restricts lateral sliding of a heat sink and thereby maintains good electrical contact between an associated CPU and an associated CPU socket.

[0009] To achieve the above object, a heat sink retaining assembly of the present invention includes a retaining module and a pair of clips. Two retaining portions are respectively formed on each of two opposite sidewalls of the retaining module. A plurality of bifurcated block portions is integrally formed on interior faces of each of four sidewalls of the retaining module. A gap is defined between each block portion and its corresponding sidewall, and each gap receives a resilient member. Each resilient member includes a guide portion and a pressing portion. A heat sink is received in the retaining module via the guide portions. The heat sink is restricted by the pressing portions from sliding in lateral directions relative to the retaining module. The clips are engaged with the retaining portions of the retaining module. The heat sink is thereby securely fastened to the retaining module and to an associated CPU package.

[0010] Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of a preferred embodiment of the present invention with the attached drawings, in which:

[0011] FIG. 1 is an exploded isometric view of a heat sink retaining assembly in accordance with a preferred embodiment of the present invention, together with a heat sink and a CPU package that is mounted on a motherboard;

[0012] FIG. 2 is an enlarged exploded isometric view of a retaining module of the retaining assembly of FIG. 1; and

[0013] FIG. 3 is an assembled view of FIG. 1.

[0014] Referring to FIGS. 1, 2 and 3, a retaining assembly in accordance with a preferred embodiment of the present invention comprises a retaining module 1 and a pair of clips 3. The retaining assembly is for mounting a heat sink 2 onto a CPU package (not labeled) that itself is mounted on a motherboard 4.

[0015] The retaining module 1 comprises a rectangular base 10, a pair of parallel first walls 17 extending perpendicularly upwardly from two opposite edges of the base 10 respectively, and a pair of parallel second walls 17′ extending perpendicularly upwardly from another two opposite edges of the base 10 respectively. The second sidewalls 17′ are perpendicular to and respectively connect between the first sidewalls 17. A pair of spaced retaining portions 12 is provided at top parts of each of the second sidewalls 17′. Each retaining portion 12 may comprise a protrusion, or alternatively may define a hole. In the preferred embodiment, each retaining portion 12 defines a hole (not labeled). An opening 11 is defined in a center of the base 10, for receiving the CPU package therein. Four holes 16 are defined in four corners of the base 10 respectively, for mounting of the retaining module 1 on the motherboard 4 using screws. A bifurcated block portion 13 is integrally formed on an internal face of each first sidewall 17. A pair of bifurcated block portions 13 is integrally formed on an internal face of each second sidewall 17′. A gap 15 is defined between each block portion 13 and its corresponding sidewall 17, 17′, for receiving a resilient member 14 therein.

[0016] Each resilient member 14 includes a central offset pressing portion 18, a slanted guide portion 19 extending upwardly from the pressing portion 18, two oblique spring portions 182 respectively extending from opposite ends of the pressing portion 18, and two wedge portions 20 respectively extending from free ends of the spring portions 182. The wedge portions 20 are coplanar with each other.

[0017] Each clip 3 is substantially an elongate strip. The clip 3 comprises a central horizontal portion 33, and two resilient arms 35 depending from opposite ends of the central portion 33 respectively. A hook 34 is formed at a distal end of each resilient arm 35, for engaging with a corresponding retaining portion 12 of the retaining module 1. A cam structure 31 is pivatably attached to in the central horizontal portion 33, and a handle 32 extends from the cam structure 31.

[0018] In assembly, the retaining module 1 is mounted on the motherboard 4 around the CPU package. The wedge portions 20 of the resilient members 14 are engaged in the gaps 15 of the retaining module 1. The resilient members 14 are thus fastened to the retaining module 1. The heat sink 2 is pressed onto the retaining module 1. The guide portions 19 of the resilient members 14 guide the heat sink 2 into the retaining module 1 until the heat sink 2 is resiliently held between the pressing portions 18 of the resilient members 14. The heat sink 2 is thus restricted by the pressing portions 18 from sliding in lateral directions relative to the retaining module 1. The hooks 34 of each clip 3 are engaged with corresponding retaining portions 12 of the retaining module 1. The handle 32 of each clip 3 is rotated so that the cam structure 31 presses against the heat sink 2 and causes the central horizontal portion of the clip 3 to resiliently deform upwardly. The heat sink 2 is thereby securely fastened to the CPU package and the retaining module 1.

[0019] In alternative embodiments of the present invention, other kinds of resilient clips can be used instead of the above-described clips 3 of the preferred embodiment of the present invention.

[0020] It is understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.