Future Lead-Free Solder Alloys and Fluxes - Meeting Challenges of Miniaturization

Miniaturization and green manufacturing are the electronics industry´s leading trends. New Pb-Free solder alloys must have special characteristics, such as reduced melting temperatures and wetting speeds, while increasing solder spread. These alloys should display finer grain structure, reduced voiding tendencies, and low IMC platelets formation, yet have high corrosion, electrochemical migration and oxidation resistances. The nature of future no-clean fluxes must also be taken into consideration, complementing these greener alloys by being probe-testable, halogen-free, with greater fluxing action, lower activation temperature and reduced spattering. The key is charring resistance and the oxidation barrier, which protects the alloy from surface oxidation.