Selective wave soldering Wave soldering Reflow oven Screen Printer Dispenser Software system Peripherals Vertical Oven
The main equipment of SMT production line includes printer, dispenser, chip mounter, reflow oven, and other peripheral devices including loader, unloader, buffering conveyor, inspection equipment, back repair equipment and cleaning equipment, etc. The basic complete SMT production line equipment is as follows.
(1) The printer is located at the front of SMT line and used to print solder paste or SMT glue. After aligning the hole of the stencil with PCB pad, through the movement of the squeegee, the solder paste or SMT glue on the stencil will be placed on PCB pad or corresponding position so as to the components mounting preparation.
(2) The dispenser is mainly used for coating solder paste or SMT glue, through the pressure of vacuum pump; It can dispense the materials (SMT glue or solder paste) to the designated position according to the pre-set position. It is suitable for small batch and multi-product production and there is no need to replace, make more molds, which is greatly shorten the production cycle in the production process.
(3) The chip mounter, also known as the pick and place machine, which is located behind the printer or dispenser. Its main function is to accurately pick the specified materials from the specified position and place them correctly to the specified position through the program setting. SMT production line mounting and production capacity mainly depends on the SMT machine speed and precision and other functional parameters. This equipment is the highest technical, the most complex and expensive equipment in SMT production line.
(4) The reflow oven is behind SMT mounter. Its function is to provide a heating environment to melt the solder paste on the PCB which is printed by the printer, so that the surface mounting components and PCB solder pad can be reliably combined through the solder paste alloy.
(5) The wave soldering machine is behind the reflow oven for welding plug-in components with large pins, through electric pump or electromagnetic pump the molten solder will be in wave shape, and it can be added nitrogen to solder pool also; through the solder wave, PCB with components, to weld PCB components, pins, or PCB pad.
(6) The function of SMT inspection equipment is to inspect the assembly quality and welding quality of the mounted PCB. There’re magnifying glass, microscope, AOI, ICT, X - ray testing system, FT, etc. According to the inspection need, the installation position is customized.
(7) The back repair equipment is to rework and repair the detected PCB. The tools of it will be electric soldering iron, BGA repair table, etc.
(8) The purpose of SMT cleaning equipment is to remove the materials which will affect the electrical performance or the harmful welding residues on the PCB, such as flux. For clean-free solder, there’s no need to use cleaning machine. The cleaning equipment is usually ultrasonic cleaning machine with special cleaning liquid, its position of SMT line is not fixed, can be online or offline.