The circuit board has a groove in a section of {HEAD ~ a surface} of {TAIL ~ the circuit board} 
of
The circuit board has a groove in a section of { HEAD ~ a surface } of { TAIL ~ the circuit board }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL