{HEAD ~ A solder alloy} making {TAIL ~ layer} for preventing dissolving and diffusion of tin into tin based lead free solder is thinly formed on a UBM layer 
making
{ HEAD ~ A solder alloy } making { TAIL ~ layer } for preventing dissolving and diffusion of tin into tin based lead free solder is thinly formed on a UBM layer
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH