In order for surface mount contract manufacturing , a special method known as surface mount technology or SMT is used. With this, electronic circuits are produced whereby the components are mounted onto the surface of the printed circuit board directly. Once complete, the device becomes known as a surface mount device or SMD.
When the surface mounting technique was first developed, it was referred to as planar mounting. This technology was introduced during the 1960s and then by the 1980s, it had become one of the most widely used options. In fact, IBM provided a large portion of the pioneering work for surface mounted assemblies.
Within the field of engineering, surface mount assemblies have become more popular than the older method used called through-hole technology. With that method, components are fitted using leads made from wire into holes drilled into the circuit board. This particular method has been around for a long time and while it works, more and more professionals depend on surface mount.
Keep in mind when there are components not particularly suited for surface mounting, which includes head-sinked power semiconductors and larger transformers. In addition, it is possible to use both surface mount and through-hole technology on the same board.
Typically, a component for surface mount technology is smaller than what is seen with the through-hole method. The reason is that either the leads are smaller or in some cases, there are no leads at all. In addition, surface mount assemblies can be made using short leads or pins of different styles, as well as flat contacts, terminations on the component body, and various solders.
Interestingly, components of surface mount technology and through-hole can be soldered without adhesive being used but only if the parts are reflow soldered first. Then to prevent solder that holds that parts securely in place from floating or reflowing, a selective molded mask is required.
Even though there is a tremendous amount of detailed involved with creating surface mounted assemblies, much of the process has now become automated. As a result, there is less labor involved and therefore, reduced cost of manufacturing. Another huge advantage of the technology is that the size and weight ranges between one-tenth and one-quarter, which in turn reduces the cost of through-hole parts that are similar.
Remember, surface mount assemblies is a term that refers to a manufacturing methodology and therefore it is often called several different things.