Causes and solutions for poor wetting in PCBA processing

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Causes and solutions for poor wetting in PCBA processing [Copy link]

In pcba processing, when the surface tension of solder is destroyed, it will cause poor soldering of surface mount components. The main manifestation of poor wetting is that during the soldering process, there is no reaction between the metals of the substrate soldering area and the solder after infiltration, resulting in insufficient soldering or solder leakage. The main reasons for poor wetting are:

1. The surface of the soldering area is contaminated, the surface of the soldering area is stained with flux, or metal compounds are generated on the surface of the patch component. All of these will cause poor wetting. For example, sulfides on the surface of silver and oxides on the surface of tin will cause poor wetting.

2. When the residual metal in the solder exceeds 0.005%, the activity of the flux decreases and poor wetting will also occur.

3. During wave soldering, there is gas on the surface of the substrate, which is also prone to poor wetting.

The methods to solve poor wetting are:

1. Strictly implement the corresponding soldering process.

2. The surface of the PCB board and components should be cleaned.

3. Choose the right solder and set a reasonable soldering temperature and time.

懒猫爱飞

1) Dust-free processing 2) Most small factories basically ignore these requirements, one is cost, the other is technology