Preparation of Fine Copper Powder With Chemical Reduction Method and Its Application in MLCC

In this paper, the preparation of fine copper powder with chemical reduction method was investigated. Polyhedron nonagglomerated monodispersed copper powders by the reaction of CuSO₄ldr5H₂O and ascorbic acid were synthesized at pH 6~7 and reaction temperature of 60degC~70degC. It was also found by X-ray diffraction (XRD) analysis that a mixture of copper and cuprous oxide could be obtained when [Cu(NH₃)₄]²⁺ was reduced by ascorbic acid. Reaction temperature and pH have great effects on efficiency and particle size of copper powders. Copper powders were applied as terminal electrode materials of base metal electrode-multilayer ceramic capacitor (BME-MLCC), and the microstructures, including cross section and interface, of copper thick film were discussed with scanning electron microscopy. The results indicated that copper thick film has a loose, porous cross section and a rough interface. The adhesion strength of copper electrode is high due to rough microstructure caused by interfacial reaction.