Growth of electrical vehicles and 5G technologies may impact the landscape of soldering equipment used for printed circuit board (PCB) assemblies. These applications require large multi-layer PCBs that contain small surface mounted devices (SMD) together with heavy transformers and capacitors. This mismatch of thermal mass creates challenges for reflow process and specifically for convection ovens. Large or heavy components usually require long total heating time which may cause small  components to overheat.