Water soluble fluxes have a high solid content and are highly active, giving them excellent soldering performance. The purpose of the flux is to help create a strong solder joints by first cleaning the metal surfaces. These are aggressive cleaners and oxidisers.
This technology is being used in liquid fluxes, flux-cored wires, solder paste etc… They rarely burn off and leave a clean surface for soldering.
In addition, water soluble flux is water based hence reduces harmful emissions and is better for the operators and the environment.
- Liquid flux – Liquid flux is a common form of soldering flux that comes in a liquid consistency, Liquid flux is applied to the solder joints, or the components being soldered before the solder is applied. It helps to clean the surfaces, improve solder flow, and enhance the quality of the solder joint.
Liquid flux is an essential material used in wave soldering; a process commonly employed in the electronics industry for soldering through-hole components onto printed circuit boards (PCBs). Before the PCB enters the wave soldering machine, liquid flux is applied to specific areas where soldering is required. This is typically done by using a spray, foam, or selective flux applicator. The flux is applied in a controlled manner to avoid excessive application and ensure it is only present in the required regions.
- Flux-Cored Solder Wire – This type of Solder wire has a hollow core filled with water soluble flux. As the solder wire melts during the soldering process, the flux is released and helps clean the surfaces and facilitate soldering. Flux-cored solder is convenient to use as it combines both the solder and flux into a single product, eliminating the need for separate flux application.
- Flux in solder paste – Solder paste is a mixture of solder alloy particles and flux. It usually comes in a semi-solid or paste form. Solder paste is commonly used in surface mount technology (SMT) applications, where components are placed on circuit boards and then soldered. The flux in solder paste helps to clean the solder pads and components, promote solder wetting, and hold the solder in place before reflow soldering.