Main defects in reflow soldering of circuit boards

Reflow soldering of circuit boards can improve welding quality because it ensures that the solder and welding metal are heated to the appropriate temperature during the welding process, thereby forming reliable metal compounds. However, due to different reasons, adverse phenomena can also occur. JEENOCE shares the main adverse phenomena of circuit board reflow soldering.

1. Solder beads: Solder beads often occur on one side of the PCB board, which may be due to template blockage or excessive amount of printed solder paste during solder paste printing; During reflow soldering, the temperature curve was not set properly, and the preheating and welding temperatures were insufficient.

2. Erecting a monument: During reflow soldering of a circuit board, during the melting stage of the solder, one end of the component rises and the other end sinks, forming an upright device. This phenomenon is called erecting a monument.

3. Solder bead formation: Solder bead formation often occurs on the solder pads of PCB boards. This phenomenon may be due to excessive thickness of the solder layer on the pads, improper setting of the temperature curve during reflow soldering, and insufficient preheating and welding temperatures.

4. Non wetting: Non wetting often occurs on pins and pads, which may be due to incompatibility between the solder and the alloy layer of the pins or pads. During reflow soldering, the temperature curve is not set properly, resulting in insufficient preheating and welding temperatures.

5. Cold soldering: Cold soldering often occurs on pins and pads, which may be due to inadequate preheating and welding temperatures during reflow soldering due to the temperature curve not being set properly.

6. False soldering: False soldering often occurs between pins and pads, which may be due to incompatibility between the solder and the alloy layer of the pins or pads. During reflow soldering, the temperature curve is not set properly, and the preheating and welding temperatures are insufficient.

7. Bridging: Bridging often occurs between pins and pads, which may be due to excessive solder, improper temperature curve setting during reflow soldering, and insufficient preheating and welding temperatures.

The above are common defects in circuit board reflow soldering, which can be judged and handled according to the actual situation.