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

Abstract

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 6 ) 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 5 0 p m to 8 0 p m 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.

Manufacturing technology effect on current pulse handling performance of metallized polypropylene film capacitors

“…Apart from the difference in the heights of the components considered for testing, and in order to understand the manufacturing technology effect on the capacitors reliability, it is helpful to focus on two important stages during the manufacturing process: edge reinforcement and the schooping process. It is believed that the quality of the edge reinforcement and the schooping process affects the quality of the end-edge contact of the final product [10,11].…”

“…The quality of the contact is particle-temperature dependent and previous work [10] proved that metallized film capacitors experience change in their electrical properties (particularly ESR and dissipation factor) with spray conditions as spray air pressure, material feeding and applied voltage. A direct consequence of the schooping conditions is the size of the pulverized zinc particles.…”

“…In the presence of the magnetic flux density B = µH (with µ the permeability of the medium), the differential magnetic force equation may be written as dF = K B ds. (10) The proposed force model with the above simplifications allows computation of the ratio of forces for capacitors with different dimensions. No real order of magnitude for the electrodynamic forces taking place in capacitors could be drawn out from this model.…”