(593b) Vertically Aligned Boron Nitride Nanotube Composites for Thermal Conductivity Improvements

As electronic components continuously become smaller, their power density increases. The increase in power density results in increased component temperatures which dramatically reduces the components performance. Commercial off the shelf thermal interface materials (TIMs) typically have thermal conductivities less than 10 W/m-K, deeming them inefficient for dissipating heat in evolving microelectronics. Therefore, there is a need for an enhanced TIM that can improve the passive thermal management of these components by exhibiting a thermal conductivity greater than 10 W/m-K. We have developed a TIM containing vertically aligned boron nitride nanotubes (BNNTs) for the direct removal of heat from critical components. Boron nitride nanotubes are nanoparticles with a structure that is analogous to carbon nanotubes, however they are composed of alternating boron and nitrogen atoms. They have high thermal conductivities with a theoretical value of 6,600 W/m-K and are wide band gap semiconductors with a band gap above 5 eV. Vertical BNNT alignment was achieved via electrospinning and material reorientation. Our material exhibits anisotropic thermal conductivities exceeding those of commercially available TIMs while remaining electrically insulating. TIM fabrication will be explained which includes the method for making a well dispersed BNNT solution as well as the alignment process. Finally, the resulting thermal and electrical properties will be discussed as well as their testing methods.