The Role Of Flux And Its Qverview
The Role Of Flux And Its Qverview – Precision Spray Fluxing – Cheersonic
Flux is usually a mixture of rosin as the main component, which is an auxiliary material to ensure the smooth progress of the soldering process. Soldering is the main process in electronic assembly. Flux is an auxiliary material used in soldering. The main function of flux is to remove the oxides on the surface of the solder and the base metal to be soldered, so that the metal surface can achieve the necessary cleanliness. It prevents the soldering process. The re-oxidation of the surface reduces the surface tension of the solder and improves the soldering performance. The quality of the flux performance directly affects the quality of electronic products.
First, The role of flux
The main active ingredient in the flux is rosin, which will be decomposed by tin at about 260 degrees Celsius, so the temperature of the tin bath should not be too high; flux is a chemical substance that promotes soldering. In soldering, it is an indispensable auxiliary material, and its role is extremely important.
1. Fold and dissolve solder mother oxide film
In the atmosphere, the surface of the base metal to be welded is always covered by an oxide film with a thickness of about 2×10-9~2×10-8m. During welding, the oxide film will inevitably prevent the solder from wetting the base metal, and the welding cannot proceed normally. Therefore, flux must be applied to the surface of the base metal to reduce the oxide on the surface of the base metal, so as to achieve the purpose of eliminating the oxide film. .
2. Fold the welded base metal and reoxidize
The base metal needs to be heated during the soldering process, and the metal surface will oxidize at a high temperature, so the liquid flux covers the surface of the base metal and the solder to prevent them from oxidizing.
3. Fold Molten Solder Tension
The molten solder surface has a certain tension, just like rain falling on a lotus leaf, it will immediately coalesce into bead-shaped droplets due to the surface tension of the liquid. The surface tension of the molten solder prevents it from flowing to the surface of the base metal, preventing normal wetting. When the flux covers the surface of the molten solder, the surface tension of the liquid solder can be reduced, so that the wetting performance is significantly improved.
4. Folding protection welding base metal
The material to be welded has destroyed the original surface protective layer during the welding process. A good flux quickly returns to the protective role of the solder after soldering. It can speed up the transfer of heat from the tip of the soldering iron to the surface of the solder and the object to be soldered; the appropriate flux can also make the solder joints beautiful.
Second, the performance of the flux
1. The flux should have an appropriate active temperature range. It starts to work before the solder is melted, and plays a better role in removing the oxide film and reducing the surface tension of the liquid solder during the soldering process. The melting point of the flux should be lower than that of the solder, but not too large.
2. The flux should have good thermal stability, and the general thermal stability temperature should not be less than 100℃.
3. The density of the flux should be less than that of the liquid solder, so that the flux can spread evenly on the surface of the metal to be soldered, cover the surface of the solder and the metal to be soldered in a thin film, effectively isolate the air, and promote the solder to the base metal. wet.
4. The residue of the flux should not be corrosive and easy to clean; no toxic and harmful gases should be precipitated; there must be water-soluble resistance and insulation resistance that meet the regulations of the electronics industry; no moisture absorption, no mold; stable chemical properties, Easy to store.
Cheersonic’s ultrasonic sprayer is an alternative flux system for selective soldering machines. The ultrasonic spray system is designed to solve the main problems of most standard fluxes, such as spray and air pressure spray. The ultrasonic spray system will spray all flux without clogging, increasing accuracy, increasing production speed and reducing overspray.
Fully automatic multi-axis ultrasonic solder spray flux system with precise selective area flux function. Advanced dot programming capabilities; simply import an image of the PCB and highlight areas that require flux. Ideal for trays and PCBs with unnecessary flux. It has been proven to reduce flux consumption by up to 93%.
The fully automatic multi-axis ultrasonic solder spray flux system has advanced spray accuracy, and the maintenance amount is reduced by 95% compared with the traditional pressure spray flux. All fully automatic multi-axis ultrasonic solder spray flux systems have ultrasonic spray performance that is non-blocking, repeatable, and low-maintenance.
