Types and characteristics of flux in solder paste
R type: refers to the flux that only uses rosin as the active component, which is free of washing, safe but not active enough, and is used for precision and high price products.
RMA type: adding low active active ingredients to rosin, although the residue after welding has no corrosion and conductivity, it may hydrolyze when the humidity is too high, so it needs to be cleaned.
RA type: the flux with strong active component added in Rosin has good weldability, but the residue is corrosive and must be cleaned.
OA type: flux with organic acid as active component has stronger activity than RA type flux.
Ia type: the flux with inorganic acid as active component has the strongest activity.
Ws: water soluble flux, residue can be washed with deionized water, and can be matched with RMA rosin.
Sa: flux with synthetic material as active component must be cleaned with CFC. Since CFC was banned, it has been changed into water washing flux.