Current source for pulse plating with high di/dt and low ripple in steady state

Abstract

One of the methods to improve the quality of the metal coats is the use of different current shapes and different polarities instead of a DC current. Many authors have reported about such improvements, especially in the porosity, equal distributed thickness of the metal coats, which leads to the significant savings of metals, energy and time in the plating process. Specifically in the manufacture of printed circuit boards where the circuit density rapidly increases, a possible solution is offered by reverse pulse plating. This paper describes a model of a pulse current source rated at 9 kW (30 V, 300 A). Combining a step-up and step-down converter into a unique circuit topology, both high current slopes in transient mode and low current ripple in the steady state were achieved. Simulated as well as experimental results, obtained from a prototype current source are presented to illustrate good behavior of the scheme.