The THR technology (Through Hole Reflow) is a placement technology for printed circuit boards(PCB) with which components for the through hole technology( THT), but also SMD components, can be processed.
With the THR process, in which the through-hole technology is integrated into the SMT technology, the assembly costs for automatic PCB assembly can be reduced, since some process steps of the THT technology are omitted. However, the prerequisite for integration is the validation of the manufacturing process as well as the adjustment of the placement parameters such as the PCB design and paste pressure.
In THR technology, THT components equipped with lead wires are processed using the reflow method. In this process, the connection holes for the lead wires are filled with solder paste. In the reflow process, the heat causes the solder paste to melt and the solder penetrates the plated-through terminal holes and bonds with the connecting wire.