Board reflow soldering improves soldering quality because it ensures that the solder and solder metal are heated to the proper temperature during the soldering process, resulting in the formation of a reliable metal compound. However, due to different reasons, there will also be undesirable phenomena, and Jeenoce shares what are the main undesirable phenomena of circuit board reflow soldering.
1. Solder beads: Solder beads mostly occur on one side of the PCB board, this phenomenon may be due to the blockage of the template or the excessive amount of printed solder paste when the solder paste is printed; During reflow soldering, the temperature profile is not set well, and the preheating and soldering temperature are insufficient.
2. Monument: In the reflow soldering of the circuit board, in the solder melting stage, one end of the component rises and one end sinks, forming a device erection, which is called a monument.
3. Solder beading: Solder beading mostly occurs on the pad of the PCB board, which may be due to the thick solder layer of the pad, the temperature curve is not set well during reflow soldering, and the preheating and soldering temperature are insufficient.
4. Non-wetting: The phenomenon of non-wetting mostly occurs on the pins and pads, which may be due to the incompatibility of the solder with the alloy layer of the pins or pads, and the temperature curve is not set well during reflow soldering, and the preheating and soldering temperature are insufficient.
5. Cold soldering: Cold soldering mostly occurs on the pins and pads, which may be due to the fact that the temperature curve is not set well during reflow soldering, and the preheating and soldering temperature are insufficient.
6. Virtual soldering: virtual soldering mostly occurs on the pin and pad, this phenomenon may be due to the incompatibility of the solder with the alloy layer of the pin or pad, the temperature curve is not set well during reflow soldering, and the preheating and soldering temperature are insufficient.
7. Bridging: Bridging mostly occurs between the pin and the pad, which may be due to too much solder, the temperature curve is not set well during reflow soldering, and the preheating and soldering temperature are insufficient.
The above are the common undesirable phenomena of circuit board reflow soldering, which can be judged and dealt with according to the actual situation.