Finite-element analysis of ceramic multilayer capacitors: Failure probability caused by wave soldering and bending loads

A two-dimensional numerical model that predicts the reliability of multilay er capacitors (MLCs) during soldering and bending is presented. The Weibull parameters used in the model are based on measurements of soldered MLC dev ices. The preheating and soldering temperatures have a dominant impact on t he failure probability, in comparison to the thickness of the nickel layer, the soft solder geometry, and the number of inner electrodes. Comparison o f calculated and measured reliability of three MLC sizes leads to the assum ption that residual stresses due to the manufacturing process or size-relat ed microstructure are important.