Chemical Anchoring

About

Background: This invention describes a novel method of anchoring and growing carbon nanotube structures on various substrates coated with thin layers of metal tsuch as gold, silver, and copper. Well-aligned carbon nanotube structures grown on substrates such as silicon wafers and copper plates can be used in electrical, photochemical, thermal and mechanical applications. Carbon nanotubes were in-situ surface functionalized during CVD growth and coated with reactive functional groups without destroying or compromising the aligned structures; the functionalized nanotubes can be transferred onto functionalized metal-coated substrates resulting in a composite with high thermal and electrical conductivity and high interfacial adhesion strength. A novel assembling process of incorporating carbon nanotubes as thermal interface materials for heat dissipation has been developed by synthesizing vertically aligned carbon nanotubes and chemically bonding the carbon nanotubes to a silicon surface. The assembling process and the carbon nanotubes/silicon structure are compatible with current flip-chip technique. Experimental results indicate that such an interface modification improves the effective thermal diffusivity of the carbon nanotube-mediated thermal interface by an order of magnitude and conductivity by almost two orders of magnitude. The interfacial adhesion is dramatically enhanced as well, which is significant for reliability improvement of the thermal interface materials.