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