FIG 3 is a bottom view of one embodiment of secondary substrate having {HEAD ~ a solder pattern} arranged to match {TAIL ~ the pre existing pattern} on primary substrate 1 
arranged to match
FIG 3 is a bottom view of one embodiment of secondary substrate having { HEAD ~ a solder pattern } arranged to match { TAIL ~ the pre existing pattern } on primary substrate 1
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH