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