Title

Carbon nanostructures as thermal interface materials processing and properties

Date of Award

2011

Degree Name

M.S. in Aerospace Engineering

Department

Department of Mechanical and Aerospace Engineering

Advisor/Chair

Advisor: Khalid Lafdi

Abstract

The power density of electronic packages has substantially increased. The thermal interface resistance involves more than 50% of the total thermal resistance in current high-power packages. The portion of the thermal budget spent on interface resistance is growing because die-level power dissipation densities are projected to exceed 100 W/cm2 in near future. There is an urgent need for advanced thermal interface materials (TIMs) that would achieve order-of-magnitude improvement in performance. Carbon nanotubes and nanofibers have received significant attention in the past because of its small diameter and high thermal conductivity. The present study is intended to overcome the shortcomings of commercially used thermal interface materials by introducing a compliant material which would conform to the mating surfaces and operate at higher temperatures. Thin film labeled buckypaper" of CNF based Materials was processed and optimized. An experimental setup was designed to test processed materials in terms of thermal impedance as a function of load and materials density, thickness and thermal conductivity. Results show that the thermal impedance decreased in conjunction with the increasing heat-treatment temperature of CNFs. TIM using heat treated CNF showed a significant decrement of 54% in thermal impedance. Numerical simulations confirmed the validity of the experimental model. A parametric study was carried out which showed significant decrement in the thermal resistance with the decrease in TIM thickness. A transient spike power was carried out using two conditions; uniform heat pulse of 24 Watts, and power spikes of 24-96 Watts. The results show that heat treated CNF was 12% more temperature resistant than direct contact with more than 50% enhancement in heat transport across it."

Keywords

Carbon fibers Thermomechanical properties Research, Nanofibers Thermomechanical properties Research, Thin films Thermomechanical properties Research, Thermal interface materials Thermomechanical properties Research

Rights Statement

Copyright © 2011, author

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