A ball grid array can then be used to connect the signal contacts and ground at {HEAD ~ the second surface} of the substrate with {TAIL ~ a circuit board} 
A ball grid array can then be used to connect the signal contacts and ground at { HEAD ~ the second surface } of the substrate with { TAIL ~ a circuit board }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL