Fluidic aligned, dense SWNTs arrays as potential die adhesive and thermal interface material

A simple, room temperature process was reported to fluidic assemble dense, vertically aligned SWNTs between two chips and connect them together. This technology has the potential capability to attach a die to its heat sink in packaging replacing the common available die adhesives by virtue of better mechanical and thermal properties. Two chips with trench about 2 μm deep on the pre-treated surface were pressed together face to face, and SWNT aqueous solution was driven into the gap between the two chips by capillary force. SWNTs beams were found to be assembled and have their two ends bonding with the two chips simultaneously. The mechanism of this phenomenon was explored experimentally and theoretically. In further, a series of experiments with different process parameters like different solution concentration, different dimensions of the trenches, multiply dipping and baking cycles were implemented, and the shear strength between the two chips with these different processing parameters was measured after removing moisture completely. In result, shear strength up to about 100 kPa was demonstrated.