PCBs are an innovation. PCBs have made circuits sturdy, small and neat as compared to early boards. This is the through hole technology of PCB fabrication. With time and requirement, the size if the PCB started appearing bigger. As this is an era of miniaturization, further reduction in size of the PCB was required. To cater to miniaturization of the circuits, surface mount technology came into effect. The components lack leads and can be soldered on the same side of the board where the circuit is.
Features of the surface mount technology
As the name suggests, components are placed on the same surface where the circuit design is soldered. This saves the other surface of the PCB substrate and it can also be utilized to design a circuit and placement of circuit components. The circuit components for surface mount technology are different from conventional components. They are flat profiled, small and give minimum height and length to the circuit.
A metallic bed is prepared for them on the circuit. The components have metallic ends. The components are placed on the bed and are soldered on the same surface. Even though they are on the same surface, a few holes need to be drilled on the board to connecting the circuits through on the two surfaces. These are called vias. They are useful in expelling heat from a circuit.
Circuit components are designed specifically for surface mount boards, ICs, resistors, capacitors, etc. all come in a very miniature and small flat profiled form. The main and the basic motive is to minimize the circuit.
Advantages
- The technology has become possible only because of the flat profile and small components. This has resulted in massive miniaturization of the circuits due to small component size, high density fabrication and utilization of both sides of the PCB substrate.
- The data speeds are very good in surface mount technologies due to small track lengths and good circuit design.
- The cost of production is low. Mass production of the components can be done and only few holes need to be drilled on the boards.
- It offers less resistance to shocks and vibrations due to less height of the boards.
- Low RF leakage and inductance at the soldering ends.
Disadvantages
- Reliability of solder joints is a major concern. With the miniaturization, soldering area is becoming minimal. They can also be damaged by impulsive jerks and potting compounds while thermal treatment.
- These boards are not compatible with breadboard sockets. Hence they are not friendly to test.
- They are not suitable for high power applications.
- Skilled operators and workforce is required to tackle the problems associated with surface mount boards.