The PCB 1 wherein the metal having {TAIL ~ a conductivity} lower than the conductivity of {HEAD ~ copper} is nickel 
The PCB 1 wherein the metal having { TAIL ~ a conductivity } lower than the conductivity of { HEAD ~ copper } is nickel
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH