Application-specific cable connections are an important component in electronics production. Many EMS companies have cable assembly as part of their service portfolio. The production of custom-made cables and strands places high demands on the manufacturing process and the products used for it. Especially the connection technology plays a decisive role, as the application areas of specific cables can be very different. The aim when using a flux in cable assembly is to achieve consistently good tinning using lead or lead-free solders. The tin plating must be controllable so that only a defined length of the strand is tinned. Any flux residues that may be present must not have any effect on the later use of the end product, for example due to corrosion or low electrical surface resistance (SIR). Furthermore, it is important that the fluxes used do not penetrate into the cable and strand sheathing, as this could corrode the strands and wires. Furthermore, the insulation of the cables can be damaged in this case. The fluxes must meet the temperature requirements of the specific soldering process. If the solder bath is run at higher temperatures, the fluxes must remain active. This is particularly important if the stranded wire is stripped during the soldering process. Fluxes have been specially developed for cable assembly that are tailored to the requirements of this production step. These include fluxes that are halogen-free and therefore less critical in terms of corrosion and surface resistance. In some applications, especially when using antioxidative materials, the activation must be intensified. In this case, a flux with higher activation must be selected, which can be produced by a different composition or a higher solid content. If the increase in the amount of activator is not sufficient, fluxes with a higher halogen content can be used. However, halogens increase the risk of corrosion and creeping currents. In this case, it must be carefully considered which goal is to be pursued with the flux. Flux experts can provide advice to electronics manufacturers. The fluxes are usually applied by dipping, sponging or brushing. Especially the latter method is often used in smaller EMS companies. It is therefore important that these companies can also purchase smaller quantities of the flux.
Do you have questions regarding this matter?
Your contact person: Markus Geßner
Company: Emil Otto