Importance of Flux in SMT Patch Soldering
When it comes to electronic manufacturing, paying attention to details is crucial, especially in the welding process. One key factor to consider is the proper cleaning of the metal and pad surfaces before welding, as this can significantly impact the effectiveness of SMT patch soldering. Flux, in particular, plays a critical role in the soldering process.
Features of Flux:
- Good thermal stability, with a temperature resistance of at least 100°C.
- Full effectiveness just before the welding material melts.
Functions of Flux:
- Promotes heat transfer to the welding area.
- Removes oxide from the metal surface.
- Prevents re-oxidation of the metal surface during high temperature welding.
- Maintains continuity of the SMT chip surface layer and improves heat resistance and solderability.
Composition of Flux:
- Additives: corrosion inhibitors, surfactants, thixotropic agents, and matting agents.
- Rosin: a natural flux widely used in SMT manufacturing.
- Solvents: such as ethanol and isopropanol, used to dissolve components and adjust properties.
- Activator: a reducing agent that purifies the surface of the solder and the welded part.
- Film formers: used to maintain spot welding and provide corrosion resistance and dielectric strength to the base steel plate.
