SMT production line, also known as surface mount technology (SMT), is a new generation of electronic assembly technology developed from hybrid integrated circuit technology. It is characterized by surface mount technology of components and reflow soldering technology, and has become a new generation of assembly technology in electronic product manufacturing. The main equipment of SMT production line includes: printing press, Mounter (upper surface electronic components), reflow soldering, plug-in, wave furnace, test packaging. SMT production line is mainly composed of surface assembly components, circuit board, assembly design and assembly process. The wide application of SMT promotes the miniaturization and multi-function of electronic products, and provides conditions for mass production and low defect rate production. According to the degree of automation, SMT production lines can be divided into automatic production lines and semi-automatic production lines. According to the size of the production line can be divided into large, medium and small production lines.

The basic process of SMT includes screen printing (or dispensing), mounting, curing, reflow soldering, cleaning, inspection and repair. SMT production process includes surface mounting process and mixed loading process. Detailed information about SMT Incoming Inspection and CTI 600 PCBA Production Control can be approached right now.

1) Surface mount technology, when single-sided assembly, all surface mount components are on one side of PCB. The process is: incoming inspection - solder paste stirring - screen printing paste - chip - reflow soldering. For double-sided assembly, the surface mount components are respectively on the A and B sides of the PCB. The process is as follows: incoming inspection - a side of PCB screen printing paste - chip - a side reflow soldering - turning board - B side screen printing solder paste of PCB - chip - B side reflow soldering - (cleaning) - Inspection - repair.

2) Mixed assembly process: when single side mixed loading process is carried out, the plug-in and surface mount components are on the a side of PCB. The process is as follows: incoming inspection solder paste mixing - a side screen printing solder paste of PCB - chip - reflow soldering of a side - a side plug-in of PCB - wave soldering or dip welding (a small number of plug-ins can be welded manually) - (cleaning) - Inspection - repair (paste first and then insert). The surface mount components are on the a side of the PCB, and the plug-in is on the B side of the PCB. The process is as follows: incoming inspection solder paste mixing - screen printing paste on a side of PCB - chip reflow soldering - B side plug-in of PCB - wave soldering (a few plug-ins can be welded manually) - (cleaning) - Inspection - repair. Or, incoming inspection - screen printing solder paste on a side of PCB - Mounting - manual soldering stock of A-side plug-in of PCB - reflow soldering - (cleaning) - Inspection - repair. At this time, the surface mount components are on the A and B sides of the PCB, and the plug-ins are on either side or both sides of the PCB. Firstly, reflow soldering of surface mount components on both sides of a and B of double-sided PCB is carried out according to the method of double-sided assembly, and then the plug-ins on both sides can be welded manually.

With the development of IC packaging towards high integration, high performance, multi lead and narrow spacing, it promotes the wide application of SMT technology in high-end electronic products. However, due to the limitation of process capability, it faces many technical problems. After 1998, BGA devices began to be widely used, especially in the communication manufacturing industry. The application proportion of BGA devices showed a rapid growth. At the same time, SMT technology has entered a rapid and good development period driven by high-end products such as communication.Electronic products show a trend of miniaturization and multi-function, especially the market of consumer electronic products represented by mobile phones and MP3 shows explosive growth, which further drives the miniaturization of surface mount components and the high density of product assembly. 0201 components, CSP, flip chip and other small and fine spacing devices have also entered the practical application of SMT, greatly improving the SMT technology. At the same time, it also improves the process difficulty. SMT assembly reliability failure analysis and visual inspection is available on AiPCBA.com.