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