What welding processes are used in SMT processing?

Soldering is an important process in the processing of SMT chips, which affects the quality of the product. Therefore, it is very necessary to understand the welding process of SMT chip processing. The three main soldering processes commonly used in SMT chip processing are wave soldering, reflow, and laser reflow.

 

Wave soldering process

The wave soldering process is mainly to firmly fix the electronic components on the printed circuit board by using SMT stencil and an adhesive, and then soldering the board patch immersed in the molten tin liquid using a wave soldering apparatus. The welding process can realize double-panel processing of the patch, which is beneficial to further reduce the volume of the electronic product, but the welding process has the defect that it is difficult to realize high-density patch assembly processing.

 

Reflow soldering process

The reflow soldering process first prints the solder paste on the electrode pads of the device through a suitable SMT template, temporarily placing the components in their respective positions, and then fabricating the pins with a reflow soldering machine. The solder paste melts again and completely wets the components and circuitry on the patch to cure again. The reflow soldering process for chip processing is simple and fast, and is a common soldering process for SMT processing plants.

 

Laser reflow soldering process

Laser reflow soldering processes are generally consistent with reflow soldering processes. The difference is that laser reflow soldering uses a laser beam to directly heat the soldered portion, causing the solder paste to melt again. When the laser stops illuminating, the solder solidifies again, forming a firm and reliable solder joint. This method is faster and more accurate than the former and can be seen as an upgraded version of the reflow soldering process.