Browse Prior Art Database

Fault-Tolerant Immersion Cooling

IP.com Disclosure Number: IPCOM000100866D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 3 page(s) / 138K

Publishing Venue

IBM

Related People

Zumbrunnen, ML: AUTHOR

Abstract

This article describes a cooling package which combines the features of immersion cooling and conduction cooling into a single fault-tolerant package. That is, if the coolant is impaired to a single chip, then another cooling path will dominate so that a catastrophic temperature is never reached; or, alternatively, if the coolant is lost to all chips, then the thermal capacitance of the hardware is engaged in a manner that insures that a catastrophic temperature is not reached before a problem is sensed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 48% of the total text.

Fault-Tolerant Immersion Cooling

       This article describes a cooling package which combines
the features of immersion cooling and conduction cooling into a
single fault-tolerant package.  That is, if the coolant is impaired
to a single chip, then another cooling path will dominate so that a
catastrophic temperature is never reached; or, alternatively, if the
coolant is lost to all chips, then the thermal capacitance of the
hardware is engaged in a manner that insures that a catastrophic
temperature is not reached before a problem is sensed.

      An illustration of a single chip site of a multi-chip module is
shown.  The major components are a Convection-Conduction Piston (CCP)
1a, Nozzle Adapter 2a, Heat Transfer/Capacitance Block 3a, and a
dielectric coolant.  The secondary elements consists of a spring 4 to
hold the CCP in flat contact 5 against an electronic chip and the
instrumentation 6 for problem sensing.

      The Convection-Conduction Piston has one end made smooth and
flat for contact with a chip, a blind axial hole from the other end,
and a controlled outside diameter for containment in holes located
within the Heat Transfer/Capacitance Block.  The CCP thermally
connects a chip to the coolant by single phase convection cooling at
its inside diameter and conduction cooling around its outside.  The
inside diameter is sized for optimum convective heat transfer of
axial flow between the inside surface of the CCP and the outside of
the Nozzle Adapter given the pressure drop allowances and clearances
between the parts.  The inside perimeter surface 1b can be rough
(shown) or can have axial fins for added heat transfer.  The depth of
the hole is chosen to provide a small thermal resistance between the
chip and impinging coolant plus a small spreading resistance between
the chip and piston's outer wall.  Similar to perimeter surface 1b,
the bottom surface 1c of the piston blind hole can be rough or can
have radial fins (shown) for added heat transfer area.  The preferred
outside diameter contour of the piston is one that provides the
smallest mean gap between the piston and hole given a set of
machining tolerances and chip tilt.

      The gap between the CCP and its containment hole is full of
dielectric coolant.  The coolant is chosen to have a boiling point
well above the temperatures envisioned to possibly occur and thereby
insure the preferred embodiment of single phase cooling.  This
embodiment provides additional safety as amounts of toxic products
(for instance, perfluoroisobutylene and hydrogen fluoride) at their
boiling points and the rate of decomposition will increase with
increased surface temperatures.

      The Nozzle Adapter is designed for high performance cooling,
and it allows for the option of cooling customization.  The adapter
variations include jet diameter(s), number of jets, distance from the
bottom of the CCP hole, the angle of the jet(s) impinge, and the
option of radial...