Browse Prior Art Database

Swivel Piston Conduction Module

IP.com Disclosure Number: IPCOM000089735D
Original Publication Date: 1977-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 76K

Publishing Venue

IBM

Related People

Antonetti, VW: AUTHOR [+4]

Abstract

In cooling high powered chips using direct conduction cooling, the path between the heat source, chip 10, and the sink, water 12, can result in many thermal resistances. The greater the thermal resistance the higher the chip temperature. The resistances are a result of chip tolerances, substrate 14 tolerance and flatness, etc.

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Swivel Piston Conduction Module

In cooling high powered chips using direct conduction cooling, the path between the heat source, chip 10, and the sink, water 12, can result in many thermal resistances. The greater the thermal resistance the higher the chip temperature. The resistances are a result of chip tolerances, substrate 14 tolerance and flatness, etc.

The cooling scheme shown in the figure uses an individual spring-loaded piston 16 in contact with the chip 10 which forms the heat removal path. Since the chips 10 can be slightly tilted with respect to the piston axis, the enlarged spherical joint 18 is provided. This allows the end 20 of the piston 16 to make complete contact with the chip 10. Although the swivel joint 18 adds another interface resistance to the thermal path, this is minimized by the enlargement of the sphere and the option of filling the joint with conduction grease. A bellows 22 serves two purposes: provides the necessary spring force between piston 16 and chip 10, and seals off the piston 16 from the outside environment. Since the bellows 22 is made of a very light material (due to low spring force), the cavity between the bellows 22 and the piston 16 is filled with a non-water soluble grease 24.

The mechanical analysis shows that with this spherical joint 18 a minimum clearance is required for the piston 16 to move vertically within the cold plate housing 26. Filling the upper and lower annulus 28 and 30 with grease produces a very low...