Functional additives inhibit crystal growth to achieve low-roughness and high-peel strength of micro-coarsening copper foil

With the global proliferation of 5G technology, advancing electronic interconnection technologies has become critically important. The development of high-quality electrolytic copper foils, essential for efficient signal transmission, has garnered considerable attention. To mitigate the "skin effect" that could impair signal transmission and to ensure robust adhesion of electrolytic copper foils to the substrate, it's necessary to roughen the copper foils. This roughening process aims to substantially enhance the peel strength of the copper foils without exceeding the bounds of acceptable roughness. An effective strategy to achieve this involves the use of additives to refine the micro-coarsened surface of the copper foils. In this context, we have explored the impact of additives such as carrageenan, guar gum, and SPS on the surface morphology, roughness, and peel strength of electrolytic copper foils. Three types of additives can improve the performance of micro-roughened copper foil. Through electrochemical tests, it was found that all three types of additives have the effect of increasing cathodic polarization. The adsorption behavior of different additives was studied through theoretical calculations. By hybriding the three additives, two micro-coarsening systems were screened to obtain the lowest roughness and the highest peel strength, respectively. At the same time, the relationship between peel strength and surface area was verified, with the larger surface area resulting in greater peel strength. Finally, the synergistic effect of the three additives on increasing cathodic polarization was verified through chronopotentiometry.