How to deal with the pollution of reflow soldering process?

Reflow welding transfers heat energy through the laminar movement of hot air. Using heaters and fans, the air in the furnace is constantly heated and circulated. The parts to be welded receive the heating of hot gas in the furnace, so as to realize welding. Reflow soldering has hot spots with uniform heating and stable temperature. The temperature difference between the top and bottom of PCB and the temperature increase along the furnace length are not easy to control, so it is generally not used alone. With the continuous expansion of SMT application and the progress and miniaturization of components, reflow soldering is continuously improved, so that the temperature distribution of each part of the furnace can be more accurately controlled, and it is more convenient for the ideal adjustment of temperature curve.

The circuit board and components are welded together by reflow soldering process. In the whole SMT production process, there are two links that are prone to pollution. The first link is in the process of printing and pasting, if you directly contact the solder paste or wipe the solder paste casually, it will cause pollution; The second step is to brush the solder paste and paste the circuit board of components into the reflow path during the reflow soldering process. Second, the soldering production is formed by melting and cooling the solder paste through reflow soldering. There are chemicals that are harmful to the body in the solder paste, which will also cause environmental pollution.

Pollution treatment method of reflow soldering process:

The main components of solder paste are tin powder and flux. Tin powder affects the performance of the whole solder paste. The difference between tin powder and alloy composition is that the metal composition of tin powder in commonly used solder paste includes 2 to 3 kinds of metals such as tin, lead, silver, copper, bismuth, etc., of which flux and lead are harmful to human body. Therefore, if reflow soldering is operated improperly, reflow soldering will cause environmental pollution. Therefore, there should be a recycling system for polluted air in reflow welding, and the smoke exhaust and ventilation of reflow welding must be done well. Reflow welding smoke filters should be installed to reduce waste gas pollution.