Strong Connection of Single-Wall Carbon Nanotube Fibers with a Copper Substrate Using an Intermediate Nickel Layer
Zhaoqing Gao, Lele Xu, Xinyu Jiao, Xin Li, Chengjian He, Hao-Zike Wang, Chunyang Sun, Peng‐Xiang Hou, Chang Liu, Hui–Ming Cheng
Abstract
Lightweight carbon nanotube fibers (CNTFs) with high electrical conductivity and high tensile strength are considered to be an ideal wiring medium for a wide range of applications. However, connecting CNTFs with metals by soldering is extremely difficult due to the nonreactive nature and poor wettability of CNTs. Here we report a strong connection between single-wall CNTFs (SWCNTFs) and a Cu matrix by introducing an intermediate Ni layer, which enables the formation of mechanically strong and electrically conductive joints between SWCNTFs and a eutectic Sn-37Pb alloy. The electrical resistance change rate (Δ R / R 0 ) of Ni-SWCNTF/solder-Cu interconnects only decreases ∼29.8% after 450 thermal shock cycles between temperatures of −196 and 150 °C, which is 8.2 times lower than that without the Ni layer. First-principles calculations indicate that the introduction of the Ni layer significantly improves the heterogeneous interfacial bond strength of the Ni-SWCNTF/solder-Cu connections.