In circuit board proofing, soldering is a very important process. So, what are the conditions for PCB circuit board welding?

1. The weldment has good weldability
The so-called solderability refers to the properties of an alloy that can form a good bond between the metal material to be welded and the solder at an appropriate temperature. Not all metals have good weldability. In order to improve the solderability, measures such as tin plating and multilayer circuit board silver plating on the surface can be used to prevent surface oxidation of the material.

2. Keep the surface of the weldment clean
In order to achieve a good combination of solder and weldment, the welding surface must be kept clean. Even weldments with good weldability, due to storage or contamination, may produce oxide films and oil stains on the surface of the weldments that are harmful to infiltration. Be sure to remove the dirty film before welding, otherwise the welding quality cannot be guaranteed.

3. Use proper flux
The function of the flux is to remove the oxide film on the surface of the weldment. Different soldering processes should choose different fluxes. When welding precision electronic products such as printed circuit boards, in order to make the welding reliable and stable, usually rosin-based flux is used.

4. The weldment should be heated to an appropriate temperature
If the soldering temperature is too low, it is unfavorable to the penetration of solder atoms, and it cannot form alloys, and it is easy to form a virtual solder; if the soldering temperature is too high, the solder will be in a non-eutectic state, accelerate the decomposition and volatilization of the flux, and reduce the quality of the solder. It will cause the pads on the printed circuit board to fall off.

5. Appropriate welding time
Welding time refers to the time required for physical and chemical changes in the entire welding process. When the welding temperature is determined, the appropriate welding time should be determined according to the shape, nature, and characteristics of the welded part. If the welding time is too long, it is easy to damage the components or welding parts; if it is too short, the welding requirements will not be met. Generally, the longest welding time for each solder joint is no more than 5s.

The above are the conditions for China PCB Manufacturer circuit board soldering, do you understand it?