Printed circuit board

Printed circuit board (PCB) is widely used for the interconnection of various electronic components in a single circuit. It consists of an insulating base substrate. A metallic circuitry is formed upon this substrate by photochemical methods. The main parts of a printed circuit board are tracks, lands and holes. PCB allows user to minimize the usage of wires, saving the space and time and to be very much reliable. This method is quite economical and there is no chance for any sort of loose connection.  The four types of PCBs are single sided PCB, double sided PCB, multilayered PCB and flexible PCB.  Single sided PCB is economical and is very easy to construct. Here copper is coated on one side and the entire circuitry is accommodated there. In double sided PCB, copper is coated on both the sides. Multilayered PCB is constructed by careful alignment of two or more PCBs. Flexible PCB is a highly flexible conventional rigid PCB. The different steps involved in the construction of PCB are preprocessing, photolithography, etching, stripping, tin plating, drilling, testing, loading of components and soldering.