Study On Organic Additives Applied To Electrodeposited Copper Foil

Electrodeposited copper foils have widely used as the conductors for printed circuit boards (PCB) and copper clad laminates (CCL).In addition, electrodeposition offers a substantially cheaper process than physical vacuum deposition (PVD) or chemical vapor deposition (CVD).In this paper copper foil was prepared by direct current electrodeposited under different conditions in CUSO4/H2SO4 electrolyte solution containing organic additives, then we used scanning electron microscope(SEM), microcomputer control electronic universal testing machine and high temperature drawing machine to investigate the effects of different additives on the microstructure and mechanical properties of 18μm electrodeposited copper foil.The results reveal that thiourea can refine grain, decrease the surface roughness and improve mechanical properties. The best result can be obtained when the content of thiourea is about 1 mg/L. Phenolphth alien also have grain refined and smooth effect, but physical properties were reduced. Phenolphth alien can act in synergy with other organic additives for the role of other additives to play better. The best result can be obtained when the content of phenolphth alien is about 1.5 mg/L.Glucose cannot refine grain size, but can improve the uniform growth of grain and elongation of copper foil.The best result can be obtained when the. content of Glucose is about 0.5 mg/L.3-mercapto-l-propanesulfonic acid sodium salt (MPS) is a grain refinement agent, leveling agent and brightener which can make the surface of copper foil smooth and flat and improve mechanical properties also, so 0.2 mg/L is the optimum amounts for the attainment of high-quality products.The effects of four kinds of additives such as thiourea (TU), phenolphth alien (PA), glucose (G) and 3-mercapto-l-propanesulfonic acid sodium salt (MPS) on the mechanical properties of electrolytic copper foil were studied. The optimal formula was as follows:TU 1.2 mg/L, PA 1.5 mg/L, G 0.3 mg/L, and MPS 0.2 mg/L.The tensile strength and elongation of copper foil at room temperature is 368.6 MPa and 6.1%,respectively, while at high temperature they are 213.7 MPa and 4.6%, respectively.The pinhole and warp is the most difficult problems of troubling enterprise production, especially for the 18μm thick (or less than 18μm thick) high-grade electrolytic copper foils which have higher frequency of pinhole production. As these defects not only results in the appearance defects in copper foil but also reduces the mechanical properties of copper foil, which degrades the rate of the copper foil.This paper discussed the influence of impurity to the defects of copper foil, and the inhibition effect of organic additives to the defects of copper foil.