AN-5241 — Guidelines for Pb-Free Soldering of Fairchild Components Based on JEDEC® J-STD 20D / IEC EN 61760-1:2006

The basic concepts behind the Pb-free SMT reflow process are the same as the old industry standard Sn63Pb37 solder used for decades in the electronics industry. The proper characterization of the equipment, with consideration given to the board component loading, as well as the selection of the appropriate materials and printing process, result in a reliable, high-yield, low-rework assembly run. Similarly, proper characterization of the Pb-free wave-solder process results in consistent wetting of the terminals and throughholes with no damage to surface mounted components on the same board. This application note presents Fairchild’s recommendation for a starting point for SMT and wave solder profiles; however, it is critical to recognize that a soldering profile that works for one board and material set likely differs from other production runs if the material or board design is different.