Preparation of VACNT TIM by a novel metallization and chemical bonding process

With power densities rapidly increasing in electronic devices, thermal management in microelectronic technology has become a crucial issue in maintaining the performance and reliability. Carbon nanotube (CNT) as a thermal interface material (TIM) has attracted extensive attention for its ultrahigh thermal conductivity, but not yet put into application due to its weak interfacial connect to substrate. A novel vertically aligned carbon nanotube (VACNT) fabrication technology using metallization and a chemical approach to bond the CNT interfaces is presented. The VACNT structure was fabricated by a thermal CVD process, and metallization of Ti/Ni/Au were used to reduce the interfacial thermal resistance. Equivalent thermal conductivity measured using laser flash analysis method was 28.49W/(m·K) after 200 thermal cycles, verifying thermal reliability and stability. CNT interfacial thermal contact resistance was measured and calculated to be 0.0652K·cm²/W, indicating a good interface connection. The study would contribute to the application of VACNTs as thermal interface materials in microelectronic packaging.