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Heatsink Exhibiting Optimized Thermal Bondline Planarity and Constant Uniform Pressure with overtorque prevention. Disclosure Number: IPCOM000202320D
Publication Date: 2010-Dec-13
Document File: 5 page(s) / 366K

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The Prior Art Database


A solution is required that mitigates the frequent, and often catastropic, side effects of assembly errors and inconsistencies associated with the attachment of heat sinks or thermal management systems to very high power LSICs, SOICs, and Microprocessors. The proposed invention simplifies the heat sink attach process, doesn't require specialized or calibrated tools or equipment to achieve uniform and constant pressure, and enables fast and efficient attachment, removal, and reattachment of the heat sink assembly with a significant reduction in risk of physical or thermal damage to a DUT.

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Heatsink Exhibiting Optimized Thermal Bondline Planarity and Constant Uniform Pressure with overtorque prevention .

The Cold Block Module (Figures 1 & 2), is the primary heat dissipative component of the invention. Chilled liquid coolant is cycled through the Module as illustrated in Figure 2 while flow rate and coolant temperature are externally controlled.

Unique input dwell and output hold chambers interrupt the linear coolant flow path slightly; and serve to equalize the input and output flow rate and temperature across the entry and exit ports of the embedded network of channeled fins. Thermal gradients are reduced and heat extraction maximized when coolant flow and temperature are uniform across the thermal interface of the Cold Block Module as well as the surface of the DUT.

The near laminar coolant flow path through the Cold Block Module, created by this unique design, minimizes coolant flow resistance, provides uniform heat conductivity at the thermal interface, and increases overall cooling efficiency.

Thermal absorption efficiency is further enhanced by an appropriate balance between coolant type, temperature and flow rate, Fin Surface area and channel size, Cold Block Module size, thermal conductivity, and the quality of the the thermal interface separating the Cold Block Module and the DUT.

Two independent fin chamber designs of 7 and 30 fins each were required for optimized system level performance of the Cold Block Module, and were designed to accommodate coolant viscosity differences between systems.

The Cold Block Module is shown (Figure 3) as it appears when installed in its Gimbaled Cold Block Attach Module and mounted on the Positioner Module.

The Positioner Module is securely attached to the board, after the DUT has been installed in its socket. The bottom surface of the Positioner Module has a raised ring region which serves to seat the DUT into the test socket at a fixed and uniform vertical depth across the DUT. This feature ensures uniform and repeatable contact pressure where the DUTs electrical interface contacts the socket pins. The bottom of the Positioner Module lays flat across the top of the DUT socket to limit the loading force exerted on the test socket contacts, constrains and uniformly distributes pressure applied to the socket pins, reduces contact wear, and maximizes socket life.

When installed in a system, the Positioner Module appears as shown in Figure 4 where the DUTs thermal interface is exposed (Top of DUT) and ready for installation of the Cold Block Module shown immediately right of the mounted Positioner Module in Figure

The installed assembly comprised of the 3 Modules is shown in Figure 5.

Spring loaded sleeves are shown in Figure 3, which mount over the four vertical


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stanchions on the Positioner Module (Figure 4). The sleeved springs are shown compressed in Figure 3 as revealed by the gapped region shown; where the Cold Block Module is elevated above the Positio...