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Method for a heatsink base and IHS for combined air and liquid cooling

IP.com Disclosure Number: IPCOM000010418D
Publication Date: 2002-Nov-27
Document File: 6 page(s) / 82K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a heatsink base and an integrated heat spreader (IHS) for combined air and liquid cooling. Benefits include improved functionality and improved ease of implementation.

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Method for a heatsink base and IHS for combined air and liquid cooling

Disclosed is a method for a heatsink base and an integrated heat spreader (IHS) for combined air and liquid cooling. Benefits include improved functionality and improved ease of implementation.

Background

        � � � � � The power dissipation of CPUs increases from generation to generation. Conventional air-cooling technology is not sufficient to maintain the CPU under the reasonable temperature in the ambient environment. One solution is liquid-cooling technology. A liquid-circulated cold plate is mounted to the CPU. However, the current cold-plate design requires certain amount of vertical height that is greater than a mobile or hand-held device can accommodate. In addition, the CPU can fail due to loss of thermal solution if the liquid pump fails or malfunctions.

� � � � � The conventional heatsink base has a pedestal shape/heat spreader (see Figure 1) or is tapered (see Figure 2).

� � � � � A conventional heat spreader made of copper or other high-thermal-conductivity material is directly attached to the package substrate by adhesive or epoxy type of sealant (see Figure 3). The heat generated from the die dissipates through the heat spreader, the heatsink, and then to the external ambient (see Figures 4 and 5). If a heatsink cannot be added due to size constraints, the heat dissipates from the heat spreader directly to the external ambient environment (not shown).

        � � � � � The heat generated from the package substrate due to substrate self-heating can be dissipated through the heat spreader. Conventionally, only a small portion of package substrate can directly contact the cold heat spreader (see Figure 6).

        � � � � � For the conventional solution, the overall thermal resistance, R(conventional solution), can be calculated as follows:�

R(conventional solution) = R1 + R2+R3

General description

� � � � � The disclosed method is a heatsink base and in IHS that can be used for both air-cooling and liquid-cooling without changing a device’s external dimensions, especially the stack-up height. The disclosed method extends the current heat spreader design by adding liquid-flow channels that are embedded in the base and added to the IHS peripheral (outside die) area. Because the liquid-cooling path is parallel to the air-cooling path for this method, the heat spreader can be used for air-cooling, liquid-cooling, or both.

        � � � � � The method provides redundancy. If liquid cooling fails due to a malfunction of the liquid pump, the heat spreader continues to dissipate heat by air-cooling, like the conventional heat spreader. Alternatively, the IHS acts like a...