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