Study of VOC-Free, No-Clean Flux for Lead-Free Soldering in Electronic Packaging
Aiming at issues existed in lead-free electronic packaging, as well as the air pollution induced by volatile organic compounds (VOC) in conventional soldering fluxes, a new VOC-free no-clean flux was formulated specifically for lead-free wave soldering. Spread test and wetting balance test were carried out to evaluate the activity of the newly developed flux with Sn3.8Ag0.7Cu lead-free solder. Besides, influence of flux residues on corrosivity and reliability of printed circuit board (PCB) was investigated by measurement of surface insulation resistance (SIR). The results showed that VOC-free fluxes required a good preheat process to obtain better soldering performance. And, flux residues of new VOC-free 1 had higher corrosivity than VOC and VOC-free 2, so the flux formulations needed to be ameliorated for the future. Due to the benefits of eco-friendly and cost saving, it is promising to successful implementation of VOC-free fluxes if some process modification is done.
Zhengyi Jiang, Xianghua Liu and Jinglong Bu
D. X. Xu et al., "Study of VOC-Free, No-Clean Flux for Lead-Free Soldering in Electronic Packaging", Advanced Materials Research, Vols. 154-155, pp. 1012-1018, 2011