Barrier layer multilayer ceramic capacitor processing: effects of termination and plating process parameters

The authors report studies on the effects of termination and plating process parameters on fabrication of multilayer ceramic capacitors intended for use as surface-mount devices. The parameters in this study included: three capacitor lots, eight termination ink types, seven termination band heights, two termination crown heights, the number of columns for nickel plating, and the time and current density for solder plating. Fifty experiments were performed; nine of these experiments were repeated to estimate experimental error. As response variables, 1830 data points each were measured for capacitance, dissipation factor (DF), and internal resistance. Four of the termination inks can be ranked together as statistically better than the other four studied. They are Dupont 4506, A, B, and dual-layer (4506 fired, 10 mils/1172D). A and B are inks formulated for the AT&T dielectric by a commercial vendor. B is ranked best for DF, DF spread, and conductance and is indistinguishable (at 90% confidence levels) from the other three for conductance spread. Termination crown height and bandwidth and solder plating had significant effects whereas nickel plating had no effect