Green Formaldehyde-Free Electroless Plating Mechanism, Kinetics, and Sustainable Bath Recycling for Conductive Copper Patterns

This research investigates the mechanism, kinetics, and sustainable bath recycling of a green formaldehyde-free electroless plating copper process for conductive copper patterns based on core–shell magnetic copper-coated-nickel nanoparticles (Ni@Cu NPs) catalyzed, which aims to understand the mechanisms governing the deposition process, optimize the plating conditions, explore the recycling of the plating bath for green fabrication flexible printed circuits (FPCs), and reduce waste discharge. By establishing mathematical models of mass transfer and electrochemical reactions to simulate the electroless plating process, the models revealed the changing trends of mixing potential, current density, and deposition thickness and can predict the progress of the electroless plating reaction. Additionally, the work establishes comprehensive kinetic equations, identifying the effects of various factors such as temperature, pH, and reactant concentration on the reaction rate and process efficiency. A key breakthrough lies in the innovative recycling strategy for the plating bath, which successfully maintains the integrity of copper pattern conductivity after 10 bath cycles with a minimal increase in sheet resistance. This controlled replenishment of reactants significantly reduces material loss and waste discharge, promoting both economic and environmental sustainability in electronics manufacturing.