This study investigates the changes in the surface characteristic, electrical and mechanical properties of copper foils electrodeposited in electrolytes with added various additives (Janus Green B (JGB), 3–mercapto–1–propane sulfonic acid (MPSA), Polyethylene glycol (PEG) and Chloride ion) under high current density. The main effect of additives on these properties was analyzed. In the group with added JGB, the crystal size on the surface became finer, and a homogeneous surface was observed. However, dented areas were observed, which decreased with an increase in chloride ions. When 100 ppm of PEG and 10 ppm of JGB were added, the fine dents on the surface increased. When a certain amount or more of additives were added, defects on the surface occurred due to competition between additives. The addition of JGB induced crystal growth in the direction of the (111) plane. Copper foils with excellent yield strength, tensile strength, and elongation could be obtained with an appropriate crystal size. The addition of JGB mainly affected crystal size and the direction of crystal growth, which is an important factor for controlling mechanical properties. PEG mainly affected elongation, and chloride ions had a primary effect on surface roughness, resistivity, and corrosion rate. Therefore, controlling additives is an effective way to significantly affect the manufacture of copper foil and produce various suitable properties in high demand.

TiO2-particles containing Co grains are fabricated via thermal hydrogenation and selective oxidation of Ti- Co alloy. For comparison, TiO2-Co composite powders are prepared by two kinds of methods which were the mechanical carbonization and oxidation process, and the conventional mixing process. The microstructural characteristics of the prepared composites are analyzed by X-ray diffraction, field-emission scattering electron microscopy, and transmission electron microscopy. In addition, the composite powders are sintered at 800℃ by spark plasma sintering. The flexural strength and fracture toughness of the sintered samples prepared by thermal hydrogenation and mechanical carbonization are found to be higher than those of the samples prepared by the conventional mixing process. Moreover, the microstructures of sintered samples prepared by thermal hydrogenation and mechanical carbonization processes are found to be similar. The difference in the mechanical properties of sintered samples prepared by thermal hydrogenation and mechanical carbonization processes is attributed to the different sizes of metallic Co particles in the samples.

This study examined the effect of current density on the surface morphology and physical properties of copper plated on a polyimide (PI) film. The morphology, crystal structure, and electric characteristics of the electrodeposited copper foil were examined by scanning electron microscopy, X-ray diffraction, and a four-point probe, respectively. The surface roughness, crystal growth orientation and resistivity was controlled using current density. Large particles were observed on the surface of the copper layer electroplated onto a current density of 25 mA/cm2. However, a uniform surface and lower resistivity were obtained with a current density of 10 mA/cm2. One of the important properties of FCCL is the flexibility of the copper foil. High flexibility of FCCL was obtained at a low current density rather than a high current density. Moreover, a reasonable current density is 20 mA/cm2 considering the productivity and mechanical properties of copper foil.