The substrate has a first surface and {HEAD ~ a second surface} spaced in a predetermined interval apart from {TAIL ~ the first surface} is prepared 
The substrate has a first surface and { HEAD ~ a second surface } spaced in a predetermined interval apart from { TAIL ~ the first surface } is prepared
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH