Thermal management for the robustness improvement of double sided SMT solder reflow

Double sided surface mount assembly (SMA) can increase packing density but also pose some manufacturing problems as it requires a two-pass reflow process. Methodologies are proposed in this paper to improve the robustness of this double pass process. Based on thermal analysis, certain combinations of surface mount components and certain sequences of the thermal reflow process should be avoided because of much higher risks affecting quality and yield. However, if such combinations and sequences are unavoidable, methods of differential heating can be exploited to improve the manufacturability of this double sided SMA.