Flux is essential in the pcba plant. Suitable fluxes not only remove oxides, prevent reoxidation of metal surfaces, but also improve solderability and transfer energy to the soldering area. Choosing high-quality flux is the secret of Jingbang Technology's brand building. Next, FASTPCBA technicians introduce four common fluxes.
1. rosin type flux;
Rosin-type flux is the most common flux. Its fluxing performance is weak, the corrosion is small, the residue is basically non-corrosive, and it remains on the substrate to form a protective film, but sometimes it is sticky and hygroscopic, and generally does not clean.
2. Water soluble flux;
Water-soluble flux, as its name implies, has high solubility in water, high activity, good fluxing performance, and the residue after welding can be washed with water. The water-soluble flux has strong deoxidation ability, strong fluxing performance, stable storage and no toxicity. The post-weld residue is easily soluble in water and does not pollute the environment. After cleaning, the pcb meets the cleanliness requirements, is non-corrosive, and does not reduce the electrical insulation properties.
3. No-clean flux;
No-clean flux refers to a flux that contains only a small amount of harmless flux after soldering and does not need to be cleaned after soldering. It is not only non-toxic and odorless, but also does not pollute the environment and has good weldability. Due to the minimal residue after welding, the pcb panel is guaranteed to be dry and tack-free, and can be tested online. And the no-clean flux can be stored for up to one year.
4. No VOC flux;
VOC is a kind of environmentally harmful substance. In recent years, due to the growing awareness of environmental protection, VOC-free flux has been developed. It is prepared by using deionized water instead of alcohol as solvent, adding active agent, foaming agent, wetting agent, non-VOC solvent, etc., according to a certain ratio. However, there is a new requirement for VOC-free flux. If the water is not completely volatilized before wave soldering, it will form solder splash (commonly known as tin), pores and voids.