What makes SMT assembly preferred option over through-hole technique?

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The procedure of soldering SMDs or surface mount devices on the PCB surface is what is termed as surface mounting. The principle on which this technology functions is a little different from the old and conventional method of soldering the components via through hole. It is a comparatively newer technology, which makes use of a different principle of soldering. Not only that, it also uses a different set of equipment for that purpose. This process is a bit more complicated and lengthy compared to its predecessor. However, it does promise to offer more electrical conductivity along with better reliability. In SMT assembly, solder bar or solder wires used for the process of embedding parts are replaced by the usage of solder paste. This technique of assembling is mostly carried out using soldering equipment, although occasionally it may be carried out manually, as well. The place in which SMT is carried out must be clean and ESD protected. This is because SMD components such as semi-conductors are highly sensitive to static charge. Clean environment is essential to avoid such components from being damaged due to static electricity. This technology offers several benefits in terms of both manufacturing and designing. In design aspect, manufacturers get to benefit in terms of noise reduction and get to save in real estate costs. SMT technique also boosts vibration and shock resistance. This is because components with low mass are used. In terms of its manufacturing benefits, SMT results in reduced board costs, a more controlled and streamlined manufacturing process, as well as cost reduction for material handling. Let us now take a look at surface mounting devices or SMDs. Special parts are used in this assembling procedure and what makes them unique is the fact that these parts do have leads as opposed to the ones used in through-hole technique. The devices used have very small metallic legs, which remain close to the components’ surface. PCBs have copper tracing on which these metallic legs are embedded during the soldering process using solder paste. Ball grid array or BGA is also a type of SMD, which does not have lead sand even no legs. These special electronic devices have small metallic spots beneath them. Solder balls are used for embedding them on the printed circuit boards.