Unraveling the Mechanism of Plasma‐Induced Curing of Particle‐Free Complex Inks for Manufacturing of High‐Performance Flexible Copper Films and Patterns

Abstract Although cost‐effective copper inks show great potential in printed flexible electronics, the poor stability and high sintering temperatures have hindered their practical application seriously. Herein, the mechanism of plasma‐induced curing of particle‐free complex copper inks is investigated systematically to realize the low‐temperature fabrication of high‐performance copper films and patterns for advanced flexible electronics. The relationships among the ink formulations, plasma characteristics, microstructures, and the properties of the printed copper patterns are identified; the mechanisms of plasma‐induced curing of copper complex inks are summarized. The fabricated copper films exhibit high conductivity (4.1 µΩ cm), excellent flexibility (bending at a radius of 2 mm), and environmental stability because of the dense microstructures and robust interface adhesion, comparable to that of electroless‐plated films. Moreover, intricate copper antenna patterns on flexible substrates can be obtained rapidly using direct writing and gravure printing methods. These results provide a feasible low‐temperature route to fabricate high‐performance copper films and patterns, promoting the practical application of low‐cost copper inks in printed flexible electronics.