(1) spectra didn't show energy range of Ni. Cu, etc.  no e-beam energy
either... hard to tell how deep is the signal come from.
(2) specimen is finished smt, you need to analyze the virgin part... don't
know those non-wetting area was contaminated with flux or not.
(3) based on 1 and 2, the sem and edx didn't means anything in terms of FA.