foil, laminated to the substrate. Chemical etching divides the copper into separate conductive lines called tracks or pcb prototipare Placa circuit paths, pads for connections, metallized holes (vias) for passing connections between layers of copper as solid conductive areas for electromagnetic shielding or other purposes. Each of the conductive layers is designed with copper tracks (similar to
is called a solder mask. Soldermask is generally green in color but can have different colors: green, red, blue, white, black. Only the outer layers need to be covered with solder mask, the inner copper layers are protected Placa prototipare pcb by the adjacent substrate layers. The soldering mask soldermask is made of a fluid
and power return. For microwave printed circuits, prototipare Placa pcb transmission lines can be laid out in a planar form, such as stripline or microstrip, with dimensions carefully controlled to ensure consistent impedance. In RF and fast switching circuits, the inductance and capacitance of the printed circuit board conductors become significant, usually