Author: Dan Lilie
Abstract: Package-on-package (PoP) is an electronic circuit consisting of superposed, electrically connected assemblies. The lower module, which is the logic component, is commonly called bottom package, on top of which usually the top package module is situated, the memory module. However, more than two packages can be stacked or vertically combined. Due to the increasing packing density, PoP solutions are found particularly often in communications technology (e.g. mobile devices). Rework of such 3D-packages requires not only the certain combination of top and bottom heating (thermal management), but also a special solder head design in order to pick individual packages up in one work step.