PCB fabrication reflow process advantages

Choosing the right welding process has a large impact on the quality of the solder joints after assembly. Which process is selected is mainly based on the assembly density of PCB printed circuit boards and SMT production line equipment conditions.

When the electronic assembly line has both reflow soldering and wave soldering  equipment, reflow soldering is used as much as possible. Because reflow soldering is compared with wave soldering, it has the following advantages:

1) Wave soldering is to directly immerse pcb fabrication electronic components in high-temperature liquid solder, and its temperature is about 250 °C, which has a large thermal stress on components. Reflow soldering is to place the entire SMA in a long temperature tunnel to slowly heat the surface, so the thermal stress on the entire printed board and components is small, which can better avoid components and printed circuit boards damage.

2) Reflow soldering only needs to apply solder on the pad. By changing the design of the stencil and the process parameters in printing, the amount of solder released on the pad is relatively easy to control. Therefore, the soldering defects are less soldered than the wave soldering and are also better handled.

2) The reflow soldering equipment has a self-positioning effect during the soldering process, that is, when the component mounting position is deviated from the mounting position of the printed board, since the solder is liquid after melting, and the liquid has surface tension, when all the soldering ends are wetted simultaneously with the corresponding pads, the pcb fabrication components are automatically pulled back to the target position under the action of the wetting force and the surface tension.

5) Solder paste is usually not mixed with impurities due to its preservation method, so the reliability of the solder material can be fully ensured.

6) Reflow soldering can use local heating or other heating methods to achieve excellent pcb fabrication welding results.