IPC 7530 PDF

During mass soldering, it is important that all solder joints reach the minimum soldering (reflow) temperature to assure metallurgical bonding of the solder alloy and the base metals to be soldered. Metallurgical bonding requires that both surfaces to be soldered, as well as the solder, reach this minimum soldering temperature for a sufficient time to allow the wetting of the solder surfaces. This document provides guidelines for the construction of appropriate profiling test vechicles and various techniques and methodologies for temperature profiling.