Preparation of Water-Based No-Clean Flux for High Temperature Lead-Free Solder
A series of water-based no-clean fluxes composed of an anion/nonion binary surfactant were investigated. The wetting behavior of Sn0.7Cu and Sn3.0Ag0.5Cu on copper with different content of binary surfactant, and the performance of the flux were tested according to the Chinese industry standard of SJ/T 11273-2002 (No-clean liquid Flux). The results showed that the wettability of binary complex was better than that of single surfactant. Two promising fluxes for Sn0.7Cu and Sn3.0Ag0.5Cu solder were selected, respectively. The fluxes showed excellent performance such as halogen-free, less corrosivity, low content of volatile organic compound (less than 5%), high spread rate (over 80%), and high surface insulation resistance (beyond 108Ω). The prepared fluxes meet the requirement of lead-free solder.
Z. F. Hao et al., "Preparation of Water-Based No-Clean Flux for High Temperature Lead-Free Solder", Advanced Materials Research, Vols. 314-316, pp. 1112-1116, 2011