Simplified mounting configuration that applies pressure force to one central location

[0001] 1. Field of the Invention

[0002] The present invention relates to mounting a block on a heat transfer device, and more particularly, for proper placement of the block over the heat transfer device to increase thermal transfer between an electronic component and heat transfer device.

[0003] 2. Description of the Related Art

[0004] Typically, removing heat generated from electronic components is a primary concern particularly when electronic components are located in enclosures with poor to little ventilation. Failure to remove excess heat results in malfunction of the electronic component. By attaching a heat transfer device to an electronic component, the device will transfer thermal energy away from the electronic component. A heat transfer device can consist of a simple piece of metal or a cold plate. Fans used in conjunction with metal heat transfer devices circulate hot air away from the electronic component. A cold plate heat transfer device consists of a pair of hoses and an inlet and outlet tube which allows liquid coolant to pass through it. As hot air is transferred from the electronic component through the base of the cold plate, liquid coolant entering an inlet valve of the cold plate removes the hot air and passes it through an outlet valve. Liquid coolant is applied to the cold plate through a hose attached to the inlet valve. Likewise, an additional hose is connected to the outlet valve for removing the liquid coolant from the cold plate. In either type of heat transfer device used, it is critical that sufficient pressure is applied the heat transfer device to ensure adequate contact with the electronic component.

[0005] Prior art heat sink assemblies disclose a number of ways of forcing a heat transfer device against an electronic component to ensure sufficient contact and pressure. To provide for adequate contact and pressure between the electronic component and a heat transfer device, a clamping mechanism applies a downward force that forces the heat transfer device against the electronic component.

[0006] An example of such a heat sink assembly is disclosed in the U.S. Pat. No. 6,665,188 to Chen. The Chen patent discloses two contact members that engage with each other and are moveable over the surface of the heat transfer device. Each contact member has a bolt and arm to facilitate moving the contact members against each other. As the two contact members engage one another, a downward force is applied against the heat sink, which applies a force against the electronic component and establishes contact between the heat sink and the electronic component. The dialing of the bolts is time consuming and may not reliably ensure sufficient contact during mass production of heat sink assemblies. Therefore, what is needed is a heat sink assembly that can distribute sufficient force across a heatsink to a localized position of the electronic component reliably and in a timely manner for mass production. Particularly when localized regions of the electronic component generate more heat than other regions.

[0007] The present invention provides a heat transfer assembly for increasing thermal energy transfer comprising an electronic component and a circuit board including an attachment point for supporting the electronic component. Additionally, a heat transfer device having a first and second side is placed against the electronic component for transferring thermal energy away from the electronic component. A block is placed over the first side of the heat transfer device and a clamping mechanism interacts between a support and the block for urging the heat transfer device against the electronic component. A locating mechanism for locating the block on the heat transfer device is used to ensure positive location between the heat transfer device and the electronic component for optimizing thermal transfer between the heat transfer device and the electronic component. Particularly, if specific areas of the electronic component generate more heat than other areas and the objective is to optimize thermal transfer over a localized area of the electronic component.

[0015] Referring to FIG. 1, a heat transfer assembly 10 is shown and comprises of an electronic component 20 attached to an attachment point 24 disposed on a circuit board 22. Additionally, a heat transfer device 17 consisting of a cold plate 18 having a first side 54 and a second side 56 and further including an inlet valve 42, inlet hose 43, outlet valve 44 and an outlet hose 45. A clamping mechanism 19 consisting of a clip 11 that applies a downward force against a block 16 after the clip 11 is fastened to a support 23. Preferably, the clip 11 consists of a locking tab 32 extending downward and is disposed on each end of the clip 11. The locking tab 32 is placed over a detent 40 disposed on a retainer frame 36. By attaching the locking tab 32 to the retainer frame 36, a clamp is formed between the clip 11 and retainer frame 36 to hold a spacer 14, the block 16, and the cold plate 18 in place for mounting these elements over the electronic component 20.

[0016] The clip 11, the retention frame 36, the spacer 14, the circuit board 22 and support 23 receive a screw 12 that threadedly engages the support 23 to sandwich these elements together. Alternatively, any fastening mechanism may be used in fastening these elements to the support 23. The spacer 14 will limit the dampening force of the screw 12 and allow the screw 12 to bottom out which ensures a nominal force between the clip 11 and block 16. By ensuring a predetermined or nominal force, damage to the electronic component 20 is avoided. To aid the operator during the fastening process, the retainer frame 36 further includes a plurality of indexing fingers 34 which engage a plurality of slots 38 disposed on the circuit board 22. The engagement between the indexing fingers 34 and the slots 38 prevent lateral movement between the base of the retainer frame 36 and the circuit board 22 during the fastening operation.

[0017] Referring to FIGS. 1, 2, 4 and 5; the block 16 contains a grooved notch 30 which allows for the clip 11 to rest on top of the block 16. During the fastening operation, the clip 11 provides force against the block 16. In turn, the block 16 applies pressure against the first side 54 of the cold plate 18 resulting in contact between the second side 56 of the cold plate 18 and the electronic component 20. A thermal compound (not shown) is applied between the electronic component 20 and the second side 56 of the cold plate 18 to increase the thermal transfer between the two elements.

[0018] Referring to FIG. 3, to ensure adequate contact between the cold plate 18 and the electronic component 20, a locating mechanism 52 consisting of a plurality of tongues 26 and a groove 28 which is placed between the block 16 and the cold plate 18. The tongues 26 are disposed parallel to one another, however alternative embodiments of heat sink assemblies may include various configurations related to the positioning of the tongues with respect to the groove. Furthermore, a plurality of grooves 28 may be used where an individual groove 28 will fit over each tongue 26. By using a locating mechanism 52 to place the block 16 on the cold plate 18, different block 16 designs may be utilized to apply localized pressure onto the cold plate 18. This is apparent as the area of the block 16 in direct contact with the cold plate 18 generates a greater force than the area of the block 16 not in contact with the cold plate 18. This is optimal for targeting specific cross-sections of the electronic component 20 which generates more heat than other regions.

[0019] Referring to FIGS. 3 and 6, as heat is generated from the electronic component 20, liquid coolant (not shown) enters the cold plate 18 through an inlet hose 43 attached to an inlet valve 42. As the liquid coolant flows through the cold plate 18 the excess heat is removed and carried away by the liquid coolant as it exits the cold plate 18 through an outlet hose 45 attached to an outlet valve 44. By circulating liquid coolant, the cold plate 18 is able to moderate and maintain a proper operational temperature for the electronic component 20.

[0020] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. The invention may be practiced otherwise than as specifically described within the scope of the appended claims.