red, blue, white, black. pcb cablaj Only the outer layers need to be covered with solder mask, the inner copper layers are protected by the adjacent substrate layers. The soldering mask soldermask is made of a fluid substance like an ink and is applied in a thin layer similar to
the printed circuit board made in recent years have greatly helped fields such as medicine and aeronautics to benefit from smaller and lighter equipment that pcb cablaj has allowed them a high degree of development and effectiveness. Today, in our house, almost every electronic device that helps us in the
terminals and electrically connect them using traces of one or more layers of copper sheets laminated on and/or between layers of conductive substrate sheets. A printed circuit board can have several layers of copper which are almost always arranged in pairs. The number of layers and the designed interconnection between them