Design and analysis of a scheme to mitigate condensation on an assembly used to cool a processor module

• Published in: IBM journal of research and development Vol. 46; no. 6; pp. 753 - 761
• Main Authors: Ellsworth, M J, Schmidt, R R, Agonafer, S
• Format: Journal Article
• Language: English
• Published: Armonk International Business Machines Corporation 01.11.2002
• Subjects: Boundary conditions; Cooling; Dew; Heat; Heat conductivity; Integrated circuits; Investigations; Load; Semiconductors; Temperature; Work stations
• ISSN: 0018-8646; 0018-8646; 2151-8556
• DOI: 10.1147/rd.466.0753

System performance of an IBM RS/6000 workstation was improved by cooling to sub-ambient temperatures the CMOS circuits of a single-chip module (SCM) mounted on a card. However, when refrigeration temperatures are sufficiently low, the temperature of all or a portion of the card on which the module is mounted can fall below the environmental dew point, resulting in unwanted condensation. Strategically placed heaters can maintain the temperature of the card surface above the dew point, but at the expense of increasing the total heat load the refrigeration unit must remove from the system. A 3D finite element analysis was used to investigate some of the key parameters that affect the thermal packaging design of a refrigeration-cooled low-temperature processor module with the objective of preventing condensation on exposed module card surfaces with minimal power input to the added heaters.