The invention relates to a preparation method for an AuSn20
alloy brazing filler metal used for packaging an
integrated circuit, which comprises the following steps: preparing gold and
tin in proportions; placing the gold and
tin into a
casting furnace; sealing the furnace and vacuumizing the furnace; rising the temperature till the gold and
tin are completely melted, controlling the temperature of the melt at 500-600 DEG C, refining for the purpose of alloying the gold and tin and degassing, and pouring the
alloy in a
graphite mould; placing an acquired AuSn20
alloy bar into a
quartz tube and heating; sealing the furnace and vacuumizing till the pressure is 4-6Pa; rising the temperature and controlling the temperature rising; after melting the alloy bar, controlling the temperature of the melt to be 500-600 DEG C, and refining for 2-3 minutes; performing the melt-
spinning process by using a vacuum
quenching melt-
spinning machine, controlling the temperature of the melt within 500-600 DEG C in the melt-
spinning process, and introducing high-pressure
nitrogen from an upper port of the
quartz tube, wherein the
nitrogen pressure is 10-15Pa; and spraying the alloy melt onto a speedily rotating
metal wheel of the vacuum
quenching melt-spinning
machine from a bottom hole on the
quartz tube, thereby acquiring a belt material. The belt material can be milled into a foil belt material or be punched into a slice or annular deeply processed product in the corresponding specification. By using the method, the product having excellent
integrated circuit property can be prepared.