METHOD OF MAKING TIN-BASED LEAD-FREE SOLDER Russian patent published in 2013 - IPC B23K35/22 

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy of light and nonferrous metals and may be used in making quick lead-free solders used in soldering electronic components and structural materials. Proposed method comprises mixing tin, copper and phosphorus and filling soldering fluxes based on organic compounds. Then, produced mix is heated to 700-800°C to add flux based on salt systems and germanium thereto. Produced mix is conditioned for 5-10 min. Cooling is performed at the rate of, at least, 10°C/s. After heating, is cooled at the rate not exceeding 10°C/s to 550-600°C and conditioned for 10-15 min. Finally, they are cooled down to room temperature. Quantitative ratio of components is selected from relationship (wt %): Cu - 0.1-3.0, Ge - 0.01-0.3, P - 0.1-0.3, Sn making the rest. Phosphorus and copper may be added to the melt as copper-phosphorus alloy.

EFFECT: higher strength of soldered joints.

2 cl