Chi-Leung Wong, Zehra Sura, et al.
I-SPAN 2002
Thermal pastes play an important role in transmitting heat generated by an integrated circuit chip from its back side to a cooling cap or heat sink which transfers the heat to the environment. Most thermal pastes are formulations of solid, thermally conducting particles in a liquid matrix loaded to very high solids content. The mixing process for such pastes is complex but important, since it determines several of the paste properties. In particular, paste rheology is related to the work imparted to the paste during the mixing process. It determines the minimum bondline between solid surfaces that can be attained with a particular paste during the assembly process, which is essentially a squeezeflow process. Paste stability depends on the amount of entrapped ah" incorporated during the mixing process; this is demonstrated by infrared (IR) visualization of the degradation of air-containing paste in a computer-chip-heat-sink gap and the absence of this degradation mechanism in vacuum-mixed paste. This paper describes two different mixing processes for highly filled thermal pastes, the associated changes in their rheological behavior, and paste degradation in chip-heat-sink gaps during thermal stressing. © 2005 IBM.
Chi-Leung Wong, Zehra Sura, et al.
I-SPAN 2002
Raymond Wu, Jie Lu
ITA Conference 2007
Raymond F. Boyce, Donald D. Chamberlin, et al.
CACM
Victor Valls, Panagiotis Promponas, et al.
IEEE Communications Magazine