Surface Mount Devices and Technology

 Long back when I used to assemble hobby electronic projects, components were mounted on printed circuit boards through holes in the circuit board on the side opposite to which the circuit was printed. The leads of the devices would be soldered to the PCB for good electrical contact. Another method used was mounting on a breadboard, which as a temporary method used mainly for experimenting with prototypes. In surface mount technology, components are mounted directly on the printed circuit board, and not through holes on the opposite side. SMT allows for better manufacturing automation, reduces cost and improves quality. More components can be fitted into a given area. SMD have smaller leads, short pins or flat contacts. When needed, both technologies may be implemented on the same PCB when components not suitable for SMT like large transformers and power semiconductors with heat sink have to be installed.




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