Here you will find all the frequently asked questions and answers that we have put together for you.
Relevant factors include the surface and drill holes of the printed circuit board, the PCB alloy and layout, storage conditions, component plating, preheating temperature and duration, the dwell time of the THT component in the solder, and the nitrogen atmosphere during selective soldering.
The flux helps remove oxides from the solder pads, thereby contributing to a clean, oxide-free surface and better wetting. Good wetting, in turn, can help reduce the formation of pores within the solder joint.
SAC alloys have higher surface tension, which makes it more difficult for trapped gases to escape from the solder. In addition, the higher process temperatures can promote gas formation from the flux, the printed circuit board, and the components. The wetting properties of SAC solders also play a role.
Possible causes include organic inclusions in the surface metallization, flux components, or oxides dissolved in the solder. Void formation is also influenced by the interaction between the printed circuit board, component metallization, solder alloy, and process control.
Voids can compromise the electrical and mechanical quality of a solder joint. Additional stress caused by vibration or temperature differences can destabilize the solder joint and, in the worst case, cause the connection between the substrate and the component to fail.
The flux must remain sufficiently active throughout the required temperature range of the soldering process. This is particularly important at higher solder bath temperatures and in processes where wire strand coatings are thermally removed during soldering.
Any remaining flux residue must not impair the electrical performance or long-term functionality of the cable connection. Of particular concern are potential corrosion and an excessively low surface electrical resistance (SIR).
The flux must allow for controlled tin plating so that only the specified length of the strand is wetted. At the same time, it must not damage the cable or strand insulation, nor have a corrosive effect on the resulting connection.
The right flux promotes uniform and controlled tinning of the strands and improves wetting with the solder. At the same time, it is essential to ensure that neither flux residue nor flux penetration into the cable or strand insulation compromises the subsequent reliability of the connection.
Prices for isopropanol (IPA) and ethanol are rising due to geopolitical tensions and the resulting disruptions in global oil and gas supply chains. Both substances are directly linked to petrochemical processes. IPA is a byproduct of petroleum refining, while synthetic ethanol is derived from ethylene. In addition, the shift of production to the Asia-Pacific region and the prioritization of domestic markets are further limiting availability. Emil Otto GmbH is responding to this development with water-based fluxes that significantly reduce this dependence.
