High-Quality Vertically Aligned Carbon Nanotubes for Applications as Thermal Interface Materials

Vertically aligned carbon nanotube (VACNT) array is an ideal form for heat dissipation in electronic packaging, due to its high-intrinsic thermal conductivity and robust mechanical properties. In this paper, we report the growth of high-quality VACNTs for the applications as thermal interface materials (TIMs). The high-quality VACNTs were grown and confirmed by the characterizations of Raman and thermogravimetric analyses. Metalized VACNT array was transferred and bonded to a metalized silicon or copper substrate. The VACNT-based TIM structure (Si-Ti/Ni/Au-In-Ti/Ni/Au-VACNT-Ti/Ni/Au-In-Ti/Ni/Au-Cu) was then successfully made after bonding to another substrate (copper or silicon). The total boundary resistance between the VACNT array and the surrounding materials was measured by an infrared thermal imaging method. Compared with the TIM sample made from carbon nanotubes grown in our laboratory chemical vapor deposition (CVD), the thermal boundary resistance of the TIM sample made from CNTs in the black magic CVD was greatly reduced from 11.6±0.5 to 3.4±0.1 mm² KW^-1. Overall, these high quality, and bonded VACNT arrays demonstrate properties promising for next-generation TIM applications.