The solder resist in the section where the groove is to be formed may be eliminated completely to expose the front surface of the circuit board, or may be eliminated so as not to expose {HEAD ~ the front surface} of {TAIL ~ the circuit board} 
The solder resist in the section where the groove is to be formed may be eliminated completely to expose the front surface of the circuit board , or may be eliminated so as not to expose { HEAD ~ the front surface } of { TAIL ~ the circuit board }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL