Analytical and finite element models of the thermal behavior for lead-free soldering processes in electronic assembly

The development of a simplified analytical model to describe the thermal history of a printed circuit board assembly (PCA) during convective reflow soldering is discussed in this paper. Verification of the assumptions was done by Finite Element Modeling, as well as comparison with experimental measured temperature profiles. The important parameter determining how fast a component heats up is the so called time constant which describes the time needed for the component to reach the set temperature. Comparison between finite element model-based estimations and measured values for three different components, CCGA, PBGA and μBGA, has been made and a reasonable agreement has been obtained.