Abstract
To study the relationship between struct ure and thermal conductivity of thermal conductive grease, it is essential to evaluate
the structure under pressure, which is the actual use environment. However, evaluating the cross-sectional shape under pressure
is difficult as grease is in a semi-fluid state. In this study, a novel method of preparing and observing a cross-section of thermal
conductive grease under pressure has been developed using a focused ion beam-scanning electron microscope. An aluminum foil/
grease/copper plate was pressurized with a vise, and the sample including the vise was immersed in liquid nitrogen to freeze and fix
the structure. Results indicated that the thickness of grease and the distribution of thermal conductive particles in the grease could be
quantitatively evaluated by this method. We found that the packing ratio of thermal conductive parti cles in the grease under pressure
remained consistently high, similar to the level before pressurization.
