Today, there exists a major push towards lead free soldering in the international electronics industry. It has presented a number of challenges in both the surface mount and wave soldering processes. The conversion of assembly processes to lead free from conventional tin/lead has put a strain on the smaller contract manufacturers in North America due to the perceived need for improved production equipment. This includes recommendations for wave solder upgrades, reflow ovens with seven or more heating zones, and repair equipment with improved preheating capabilities. These improvements require capital investment that many smaller contract manufacturers cannot afford in the current electronic economic climate. This paper details the development of a no clean lead free solder paste designed to be used with small reflow ovens with four to six reflow zones. The paper will review flux chemistry, and recommended oven settings and modifications. The conclusion is that there are viable lead free reflow soldering options that can be implemented with existing equipment and the process will continue to improve as companies gain more experience in the subtle differences between soldering with tin lead and lead free alloys.
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