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