Quality / Inspection
The main challenge for Quality Assurance / Inspection is to recognize the inherent different appearance of lead-free solder joints and flux residues that are not as easily pin probed.

Inspection
Due to inherent physical differences in their grain structures, lead-free solder joints look different than tin/lead solder joints. Whereas tin/lead joints often appear bright & shiny, lead-free joints are generally dull & grainy. In addition, wetting spread may not be as great as with tin/lead joints. However, this does not necessarily mean that lead-free joints are sub-standard or weaker than tin/lead joints. Inspection personnel must be trained on what to look for when inspecting lead-free solder joints.

Pin Probe Testing
Current test fixture settings could possibly damage lead-free solder joints. In addition, the higher reflow temperatures may result in charring and make probing through "pin probeable" flux residues more difficult. This could warrant changing flux chemistries or even residue removal in some
cases.