SMT Production Lab
Introduction: Surface mount technology is a technology in which the components are placed onto the electronic circuits (PCB). These circuits are first printed and then the components are mounted on them with the help of automatic machines known as Pick and Place machines. This technology has currently replaced the through hole technology in which the components are first put into the holes of the printed PCB through wires and then are soldered onto the board. Both technologies can be used on the same board for components not suited to surface mounting such as large transformers and heat-sink power semiconductors. Usually the size of an SMT component is much smaller than the through hole component because it may have very fine pitched and smaller leads or may contain no leads.
History: The name used for SMT was Planar Mounting. This technology was started in 1960 and got its extensive use in 1980. Most of the early work and advancement that was being done in this technology was by IBM. The design approach first demonstrated by IBM in 1960 in a small-scale computer was later applied in the Launch Vehicle Digital Computer used in the Instrument Unit that guided all Saturn IB and Saturn V vehicles. Components were mechanically redesigned to have small metal tabs or end caps that could be directly soldered to the surface of the PCB. Components became much smaller and component placement on both sides of a board became far more common with surface mounting than through-hole mounting, allowing much higher circuit densities. Terminology: There are some of the common terms that are used in the surface mount technology. These terms differentiate between components, techniques, assembly etc &Equipment and Operation: Smart feeder Feeder is the most important thing regarding SMT production line. It is the thing through which machine pick and place the components on PCB feeders support to the machines allows 8x4mm and 12×4. 8x4mm feeders have two lines means that two components can be kitted in it and 12x5mm feeders have one line means only one component can be kit on it.
Selection of solder paste Selection of solder paste is very important step and it is done according to the design of PCB if PCB contains the fine pitch components so the balls of solder paste must be very small otherwise paste will not be deposit accurately on the pads of fine pitch components and PCB will not have desired connection at the end of all procedure so careful selection is needed while dealing with fine pitch components just like RMA-20-21 T. Some relaxation can be there if there is no fine pitch components because solder paste with big balls does not effects those components and if there is an error it can be compensated in the oven.