Printed Circuit Boards Assembly Methods
Electronic components with leads coming out inserted through tiny holes in a PCB for soldering are known as thru-hole electronic components. The assembly process for these components when used in PCBs requires the use of hand soldering and wave soldering. Moreover, the temperature range used in this process depends on the solder type used. In these soldering processes, the solder is usually in the form of solder bar and it is put in a high-temperature bath. Moreover, the PCB with all its thru-hole components in holes is the passed over the molten solder using a conveyor belt. The soldering process involves the following procedures: inserting the electronic components in the molten solder, flux application, cleaning and testing. However, sometimes hand soldering is carried out in assembling companies with less with little work load or in repair work. However, a quality soldering station or solder wires and flux are use in this process.
The SMT (Surface Mount Technology) is a PCB assembly process for SMD electronic components. Unlike thru-hole components, SMDs don’t have legs or leads but they are instead mounted on the surface of a PCB. The electronic components and soldering materials used in this process are also different from those used in the thru-hole soldering process.Surface mount parts are held in place by the tension of the solder paste which is allowed to be flow continuously. This is in a bid to prepare them for the process of wave soldering. On the other hand, as the pieces are placed on the PCB, there is a literal push as the pick and place inserts them in the board. The downward pressure acting on the board can cause board flex in panels with bare minimum connecting tabs between the boards. As the pick and place moves away, the board snaps to its original position and sometimes this might flick pieces off the board.