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