Preparation of an ultra-low profile and high peel strength copper foil with rice-grain microstructures

Abstract

Driven by the booming development of signal transmission in 5G, the internet of vehicles and cloud computing, the trade-off between the low profile and high binding force of copper foil has become a prominent issue. Here, we prepared a novel copper foil (RG-VLP) with an ultra-low profile and high peel strength via electrodeposition. The physicochemical properties of the modified copper foils have been studied. The obtained results indicate that the surface of the copper foil exhibits an average diameter of 420 nm copper nanoparticles and a 52% higher surface area than bare copper foil, contributing to the improved peel strength from 0.05 to 0.5 N mm⁻¹. Further contact angle research shows that the rice-grain copper nanoparticles reduced the surface energy of the copper foil by 42%, which agrees well with the significant improvement of the surface area ratio and peel strength. Besides, cyclic voltammetry tests show that the micro-coarsening process belongs to the three-dimensional transient nucleation type.