Investigating hole filling in pin-in-paste technology for vapour phase soldering

A solution for applying through hole (TH) components in mixed assembly is the pin-in-paste (PIP) technology, when solder paste is deposited onto the plated through holes and the components are placed into the holes through the paste. An important factor in defining the quality of TH soldering is the hole filling, which strongly relies on the capillary force. In our experiments, our aim was to define an optimal paste amount for rectangular and circular pins, for different diameter plated through holes, using two types of SAC solder paste, reflow soldered by vapour phase technology.