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Thermal heatsink for a processor on a server platform

IP.com Disclosure Number: IPCOM000004699D
Publication Date: 2001-Apr-12

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a design of a thermal heatsink for a processor on a server platform

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Thermal heatsink for a processor on a server platform

Disclosed is a design of a thermal heatsink for a processor on a server platform. Benefits include the following features:

• High fin aspect ratio of 20 plus

• Sink to air thermal resistance between 0.09 C/W 0.22 C/W

• Air flow between 10 CFM 60 CFM

• Static pressure between 0.08 inches H20 .70 inches H20

• Clip or screw attachment allows pre-assembly to the package and shipped or sold as a mono-unit, providing cost benefits.

The ability to transfer heat inches a server-class chassis on a processor of up to 145W utilizing a passive cooling strategy is a new heat-sink category. Passive cooling technology provides the following benefits:

• Utilization of the air flow from an existing system fan which can be hot swappable and redundant

• Lower cost than an active sink such as a fan sink or cold plate

• High reliability with no moving parts

Figures 1, 2, 3, and 4 illustrate several implementations of the disclosed design. Figures 5 and 6 contain the performance results from testing performed on the implementations.

For testing, one section of the chassis/board assembly was simulated inches a wind tunnel to obtain the MCM processor heat sink performance of several unique heat sink designs inches terms of thermal resistance and air flow versus static pressure. This test set-up allowed for one heat sink prototype to be evaluated and manufactured instead of four for a complete mockup of a system.

The heat sink performance graphs are utilized inches the design of a system. The airflow, static pressure, and thermal resistance is obtained for this simulated geometry when an equivalent fan curve for one heat sink is known.

The test set-up is a wind tunnel that contains the processor assembly and the power pod assembly to simulate that specific section of the board and chassis, as shown inches Figures 7, 8, and 9. The power pod assembly is included because of its close proximity to the processor. The wind tunnel is foam core with a Plexiglas cover. An ebm/Papst fan draws air through the tunnel and assemblies.

Pressure readings are taken inches front of the processor assembly and following the power pod assembly. Thermocouple readings are taken at the case of the MTV 1, base of the processor heat sink, and the ambient. The air flow is calculated using three air velocity probes positioned at the entrance of the wind tunnel to obtain the velocity and the area of the wind tunnel.

The processor is simulated with the first revision thermal dummies (MTV 1). The power uses bench power supplies to the processor at approximately 102W and the four cache chips at 28W for a total of 130W.

The heat sinks have on overall size of 2.85 inches wide X 5.0 inches long X 2.0 inches tall. The fin area was 2.85 inches wide X 43 inches long X 1.9 inches tall. The configurations are:

1) Bonded augmented fin

2) Cast fin, version 1

3) Cast fin, version 2

4) Convoluted fin

5) Cast fin, copper, version 3

6) Stamped feature fin (turbulent enhancer)

7) Dual fa...