Solder Mask (S/M) Solder Mask, Solder Mask, and Solder Mask Although the Solder Mask is more general, it is more like a Solder Resist. The so-called solder mask refers to the part of the circuit board surface that is not intended to be soldered. It is covered with a permanent resin film and not tinned. This layer is called S/M. In addition to solder masks, green paint can also protect and insulate the covered circuits.
5 Axis Breakout Board For Stepper Motors,3Axis Cnc Nema17 Stepper Motor With Circuit Board ,3Axis Cnc Stepper Motor Kit With Interface Board, Driver,Power Supply
Dc Brushless motor Co., Ltd. , http://www.nbhybridmotor.com