Criteria for evaluating poor solder joints in PCBA

In the process of PCBA production, due to some unstable factors, the solder joints of PCBA will produce defects. For PCBA welding spot, there is generally an acceptable range, beyond a certain limit, will affect the reliability of the product, will be judged as defective.

The evaluation criteria for poor PCBA solder joints are as follows:

1. The pad is not completely covered by solder

The bare edges and corners of the non-circular pad should be judged as poor welding spots.

2, corrosion

Parts foot or green paint quality deterioration, production discoloration is poor solder joints.

3, icicles

Component tin spot protrusion exceeds 0.5mm.

4, tin

A cracked or cracked solder.

5. Welding spot width

A spot width less than 75% of the component end width (W) or less than 50% of the pad width (P) is undesirable.

The above are some evaluation criteria for poor PCBA solder joints. For A more comprehensive evaluation criteria for PCBA solder joints, please refer to the acceptance criteria for ipc-a-610e electronic assembly.