Setup Flux is applied first to the bonding surfaces and then heat is applied to the joint area. The temperature required is just above the melting point of the solder. The solder is allowed to flow in the joint. After reflow, the solder is allowed to cool naturally and re-solidify. However, it is difficult to clean off after the process.
Intermediate fluxes contain organic compounds and decompose at soldering temperatures.
They are suitable for all materials that are solderable with mild fluxes. They are a good choice for electronic and critical soldering applications. Common Problems Low unit strength. If the temperature is too high, a strong joint cannot be created.