Analysis of Pin in Paste Soldering on Printed Circuits Boards Assembly Using Lead Free Solder Paste

The THC (Through Hole Components) assembly in a SMT board using Pin-in-Paste (PIP) process was studied and implemented using SAC lead-free solder paste. The main idea of this process is to solder in the same thermal step THCs and SMDs (Surface Mount Devices), eliminating the step of wave soldering which is the most used in electronics assembly today for THCs. As results one could achieve reduction on production time and costs, as well as improvements in soldering quality and also environmental aspects. The experiment was conducted to identify the best PCB and stencil design parameters. Printing and reflow parameters were also considered to reach the best solder joints. Some problems could be found with solder excess but the solder quality of the reflowed boards was acceptable for almost all components.