both to connect them electrically and to fix them mechanically. Printed circuit boards are used in almost all electronic products pcb and some electrical products. Currently, the production and assembly of printed circuits are automated. Electronic computer aided design software is available to do much of the layout
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 wires on a flat surface) that provide electrical connections on pcb that conductive layer. Another
plane for shielding and power return. For microwave printed circuits, 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 pcb become significant, usually unwanted, circuit