ABSTRACT
The key to this success is process optimization, which takes into proper account the differences between lead-free and Sn-Pb wave soldering.
9.2 DIFFERENCES FROM WAVE SOLDERING WITH SN-37PB
SOLDER
The most significant factor in wave soldering with lead-free alloys is that the superheat (i.e., the difference between the melting point of the solder and the solder bath
temperature) is smaller, which is usually the case in wave soldering with traditional Sn37Pb (Table 9.1). This means that process controls have to be tight enough to keep all joints within that smaller process window until wetting and fillet formation have been completed for all joints and, most importantly, in wave soldering, until the excess solder has drained off the joints.
