Characterization of metal contact layer prepared by arc spray method and their effects in metallized film capacitor

Arc spray method has been widely used as contact layer forming method for lead welding in metallized film capacitor. The materials used as contact layer are Zn and Zn-Sn alloy etc. Metallized film capacitor show the change of electrical properties, particularly, equivalent series resistance (E.S.R) and dissipation factor (tan δ) with spray conditions of spray air pressure, material feeding speed and applied voltage. In this study, morphology, size and temperature of sprayed particles were measured and their effects on electrical properties were investigated. The size of particles is about 50 μm to 80 μm and the shapes of many particles is irregular form. The uniform small particles sprayed at 4bar were deposited densely, therefore, the capacitors made of these particles had low equivalent series resistance and low dissipation factor. After withstand current test, the capacitors with contact layer of smaller particle size show the smaller change of capacitance and dissipation factor